Direct mail lead valuation

[Ken K]

Evaluating the results of some direct mail testing I've done, I find that I'm getting some responses from owners who've recently decided to sell their very marketable house but haven't yet spoken to a real estate agent. I'm wondering how much a real estate agent might be likely to pay me for these listing leads, either at a fixed purchase price to be paid immediately, or at a higher price to be paid upon the sale of the property. Any advice or opinions on this would be much appreciated. Thanks.

Ken