How much should I charge for this?

Happy Holidays! My name is Marshall and I specialize in generating exclusive home-buyer leads for Agents, Brokers and Mortgage Lenders. I basically have a set system that allows me to generate a ton of qualified leads right from my websites.

My current employer has reported that he pays upwards of $200 per lead sometimes from other service providers and yet I've heard from other agents that they pay around $50 per lead. So the gap is quite large.

My leads are high-impact and ready to go. I get the full contact details including name, address, phone, email and zip code where they are looking to buy homes. Then I get the search criteria like # of rooms, # of bathrooms, stories and price range. Then I take it one step further and find out if they've been preapproved for a loan, how good their credit is and if they have cash for a down payment.

I'm ready to go out on my own and am looking for answers as to how much I should charge up front for each lead? Should I charge $50 up front and $150 if the lead turns into a sale? What do you think I should charge for my leads?

BTW: The leads that I get are home-buyer only and usually fall into people wanting to buy throughout the Bay Area of California. Thanks!