As one example, when a user describes a pain point, ask them what they’ve tried to solve it. Have they bought some other product that didn’t work out? Built internal tooling? If it’s merely annoying but not worth fixing today, that likely foreshadows a tough road ahead for a paid solution.
I like that question because it can avoid the trap of all the end users agreeing something is a problem, but not being interested in spending money on solutions. Quite a few developer SaaS tools fall into this category.
A lot of people are bullshitters who say they would pay for your product but... only if it gets this additional feature or works differently. That gets implemented. They still won't pay.