Have you taken a look at an affiliate network like Maxbounty? They publish their current rates here: http://www.maxbounty.com/showoffers.cfm

If leads are delivered real-time and exclusive, prices go up. It also matters what the traffic source is: personally I have only generated leads from search engine traffic as that is some of the highest quality you can get. Finally the more information the lead submits, the more valuable it is.