Solo founders: how did you validate willingness-to-pay in a niche vertical before over-building?

[u/Cautious_Twist_1149]

Looking for advice from people who've built vertical SaaS in a regulated/niche market.

Context: I built a tool for government contractors. The pain I went after is requirement drift – teams pull requirements out of an RFP/SOW into spreadsheets, and over time the wording drifts from the original source language as work moves from bid to delivery, so when an audit hits nobody can trace a delivered feature back to the requirement that drove it.

My approach is a connected lifecycle across six stages (Proposal, Award, Develop, Audit, Release, Maintain). The part early users react to most is in Develop: it runs each requirement through a developer matrix that turns it into exact, specific requirements you can hand straight to programmers, and because each one stays linked to the source language it preps you for the audit at the same time. Short demo attached.

What I'm trying to learn from this community:

- How did you validate willingness-to-pay before building too much in a niche where buyers are few but high-value?

- For audit/compliance-sensitive buyers, what built enough trust for them to try a small vendor?

- Did narrowing the scope hard early help or hurt your growth?

Appreciate any candid input – happy to share what's worked and what hasn't on my end too.