Why wont the seller give me a asking price?

[Josh Fralish]

I found a house that is for sale by owner. I've done some research on it and it looks like a good buy for the right price. The houses in this area sell for cheap but this house has the best curb appeal on a average size lot. Not a bad neighborhood either. Anyways I have asked the seller for the asking price and they have avoided the question 3 times. He returns with "what is your point of purchase"? I'm not sure how to approach this because I dont want to loose the deal before it begins.