build vs buy custom software kajabi cost coaching

Build vs buy: when a coach should invest in custom software

Every growing coach hits the same fork in the road.

You’re paying for Kajabi, plus Zapier, plus a scheduler, plus a community tool, plus the three other things holding it together. The bill climbs every time you add clients. The workarounds pile up. And one day you think: should I just build my own?

Then you Google “build vs buy”, get a wall of generic SaaS advice written for enterprise IT departments, and close the tab none the wiser.

So let’s do this properly, for coaches, with real numbers. Not “custom is always better” (it isn’t) and not “just use Kajabi” (sometimes wrong). The actual question is narrower and more useful: which parts of your business should you rent, which should you own, and when does owning start to pay?

The question isn’t build vs buy. It’s which parts.

Here’s where most people go wrong. They treat it as one big decision: stay on off-the-shelf tools, or rip everything out and build a custom platform. All or nothing.

It’s never all or nothing. Your business is made of parts, and the right call is different for each one.

Take payments. You’re not going to build a payment processor. Stripe exists, it’s brilliant, it’s a commodity. Buy it, every time. Same with video calls, email sending, file storage. These are solved problems where someone else’s tool will always beat anything you’d build.

Now take how you deliver your framework. The specific sequence, the way you onboard, the accountability rhythm that gets your clients results, the thing they actually pay you for. That’s not a commodity. That’s how you compete. And that’s the part Kajabi was never built to run, because Kajabi has to serve a yoga teacher and a stock-trading course and you, all from the same template.

There’s a clean test for this, borrowed from a build vs buy framework that cuts through the noise: is this software a commodity, or is it part of how you win? If it’s a commodity, buy it. If it’s how you win, that’s the part worth owning.

Why “just buy it” feels safe and quietly isn’t

Buying is the default because it feels low-risk. No upfront cost, cancel anytime, someone else handles the maintenance. And for a while, that’s genuinely the right call.

The problem is what happens as you grow. The rented stack doesn’t grow with you cleanly. It sprawls.

Businesses underestimate their own software usage by about 40%, on average: for every 10 tools you think you’re running, there are really 14. The bolt-ons multiply because each gap in your main platform gets patched with another subscription. And a lot of that spend is dead weight. Across the wider software market, 52.7% of SaaS licences sit unused, according to Zylo’s 2025 data. You’re paying for seats and tools you’ve half-forgotten.

Then there’s the regret. Gartner found 68% of fast-growing businesses regret a software purchase, and 31% have replaced software specifically because they couldn’t customise it to fit how they work. That last number is the coaching story exactly. You don’t outgrow Kajabi because it’s bad. You outgrow it because it can’t bend to your method, and eventually you’re spending more time forcing your business through its shape than serving clients.

If that’s where you are, the five signs you’ve outgrown Kajabi, Teachable, and Skool lays out the tells in detail. The short version: when you’re paying more in workarounds and lost time than the tools themselves cost, the “safe” option stopped being safe.

The maths: when owning gets cheaper than renting

This is the part coaches actually want a number on. So here’s how it works.

Renting starts cheap and gets more expensive forever. Every month you pay the subscriptions, and the bill rises as you add clients, seats, and bolt-ons. Owning is the opposite: a big cost upfront to build, then a small, flat running cost (hosting, AI inference, Stripe, monitoring) that’s roughly £150 to £400 a month regardless of how many clients you add.

Plot those two lines and they cross. Before the crossover, renting is cheaper and you should rent. After it, you’re burning money you’d have kept by building. For a lot of growing coaching businesses that crossover lands somewhere in the first 12 to 18 months, and everything after it is saving.

We built a tool that runs this on your actual numbers, so you don’t have to guess. Plug in your current tool spend, your revenue, your client count, your growth target, and a build price, and the build vs buy calculator shows you the exact month a build pays for itself and what you keep over three years. If you want the tool-by-tool breakdown of what you’re spending right now first, the tech stack cost auditor totals it including the cost of your own admin time.

One honest note on the maths: the cost saving is the smaller half of the case. The bigger half is the revenue you open up by delivering your framework without your calendar in the way, which is the whole point of productising in the first place. The calculator leaves that out on purpose, so the number it gives you is the conservative one.

When you should not build (yes, really)

Custom software is the right answer often, but not always. Building before you’re ready is a good way to spend £20k on something you outgrow in a different direction six months later. Stay on off-the-shelf tools if any of these is true:

  • Your framework isn’t settled yet. If you’re still changing how you deliver every few months, you don’t want it set in software. Keep iterating on cheap, flexible tools until the method is stable. Build encodes your process, so the process needs to be worth encoding.
  • You’re under 15 to 20 active clients. The maths rarely works below this. The rented stack is cheap enough at low volume that the crossover is years out. Grow first.
  • Your bottleneck is sales, not delivery. If your problem is filling the programme, not running it, a platform won’t fix that. Spend the money on getting clients before you spend it on serving them better.
  • You want the cheapest possible option, full stop. Custom isn’t it on day one. If price is the only lens, rent.

There’s no shame in any of these. The platform readiness quiz runs you through framework, demand, operations, and business model in a few minutes and tells you honestly which side of the line you’re on. Most coaches who take it and aren’t ready are glad they checked before spending.

The signs you’re past the line

The flip side. You’re probably ready to own rather than rent when:

  • Your framework is documented and proven. You can teach it, and it gets results consistently, not just when you’re personally in the room.
  • You’re spending real hours every week patching tools together, and you can feel it eating into the work that actually pays.
  • The monthly tool bill plus the lost time is clearly more than a flat running cost would be. The calculator confirms this in about a minute.
  • You’ve hit, or you can see, the revenue ceiling where adding clients means adding hours you don’t have, and the tools are part of what’s capping you.

If three of those four are true, you’re not asking “should I build” anymore. You’re asking “what, and when”.

The option most coaches forget exists

When people hear “build”, they picture hiring developers. That’s the version that scares them, and rightly so. A small in-house engineering team runs well over six figures a year before it ships a single feature. No coaching business should do that.

That’s not the only way to build. The third option is partner-build: a studio designs and ships the custom platform for you, for a fixed price, then hands it over. You own the software and the running costs stay low, but you never carry a payroll of engineers. It’s the route that makes custom realistic for a business your size, and it’s the one we run. For a full breakdown of what that costs and what you get for it, the bespoke coaching SaaS cost article has the real numbers.

How to decide this week

You don’t need a six-week strategy review. Do this:

  1. Add up what you’re really spending. Run the tech stack cost auditor. Include the admin hours, not just the subscriptions.
  2. Run the crossover. Drop those numbers into the build vs buy calculator and see the month a build pays for itself on your actual figures.
  3. Check you’re ready. Take the platform readiness quiz. If it says “more reps first”, believe it and come back in six months.
  4. If the numbers say go, get a real quote. A proper scoping conversation will tell you what your specific build costs and what it replaces, which beats any calculator estimate. For a sense of the range first, how much a custom coaching platform costs in 2026 lays out the numbers and what moves them.

Build vs buy was never a question about software, really. It’s a question about whether the thing you do is standard enough to rent or distinct enough to own. For most coaches with a proven framework and a growing book, the answer is sitting in plain sight. The only real question left is timing.

Want a real number instead of an estimate? Book a free architecture audit. We’ll price your build, map exactly what it replaces, and show you the payback on your actual stack, before you commit to anything.

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