"$29 a user per month" sounds cheap. It is genuinely cheap for the first ten users. It is rarely cheap for an organization at scale, and almost never the right baseline for an honest build-versus-buy comparison.
Hidden costs we keep watching companies absorb
Per-seat sprawl. A $29 seat × 80 employees × 12 months is already over $27,000 per year for one tool. Multiply by the five SaaS tools your operations team is using and the math is closer to a senior engineer's annual cost — which, applied differently, could have replaced the lot of them.
Integration tax. SaaS platforms only talk to each other through paid integration layers (Zapier, Make, native marketplaces) and usually charge per record synced. We have seen integration spend exceed the underlying SaaS licenses on more than one project.
Data lock-in. The "we own your data" promise tends to mean a CSV export. Operational history — the audit trail, the relational structure, the metadata — usually does not come along. Switching costs become switching impossibilities.
Workflow drift. Each SaaS tool comes with opinions about how the work should be done. Over time your team's actual workflow drifts to match the tool, not the other way around. That drift has a real cost in operating efficiency that does not show up on any invoice.
When custom flips the math
Custom software stops looking expensive in three specific scenarios: when your workflow is genuinely a competitive differentiator, when your team size pushes total SaaS spend past $50,000–$100,000 a year for a single workflow area, and when you need data and AI integrations that SaaS vendors charge you to enable per record.
If two or three of those apply to you, the math has probably already flipped. The honest comparison is rarely "build vs the sticker price." It is "build vs the all-in cost of running this SaaS stack for five years." Run that number first — the answer surprises a lot of teams.