ASK HN: Tips for surveying customer interest on the cheap?

A few friends and myself are in the beginning stages of working on a consumer oriented product. Our target demographic is the stay at home housewife ages 30-40. As you can imagine, none of us fall in line at all with this demographic.

As we've been developing the idea, the phrase "I don't think our target demographic would be interested in this" is coming up quite often. In the end though, I think we've made a lot of assumptions about a group of people we don't relate to very well. I'd like to verify those assumptions.

What can you recommend as a cheap method for surveying customer interest in a new product?