What you should NOT do is ask them “Would you buy it?” especially not “Would you buy it for $xxx?”
What you can do is ask them what they have done to solve the problem you are talking about. For example, did they spend $$ in the past 12 months to buy some product or service that solves some aspect of this problem? That is a good indication that there is a real pain that they will pay money for.
You should NEVER do pricing research in person. Always do it via one of the standard survey vehicles, quantitatively. See Elaine Chen’s “A primer on primary market research” on Slideshare for details.
This article builds on content developed by the Martin Trust Center for MIT Entrepreneurship for MIT's Orbit Knowledgebase and is licensed under CC BY-NC-SA 4.0.