How to validate willingness to pay and feature priorities for a freelance graphic de

[BrandonAM]

I've spent the last six months developing a SaaS tool for freelance graphic designers to manage client feedback, and I'm ready to start building the full version. Before I invest more time and money, I need to conduct proper market validation to ensure I'm solving a real pain point. I've created a landing page and am planning to collect emails, but I'm unsure how to structure interviews or surveys that go beyond "would you use this" to uncover genuine willingness to pay and feature priorities.