How much do  I pay for a finders fee  

If I understand your question correctly and you are asking how much you should offer as a finder's fee then it would probably depend on what it is you are looking to be found.

benjy, this is strickly an investment banking transaction. regardless of the amount, it is customary to pay 5% of the cash amount plus 5% in options.

if you are selling an investment, then I assume then you are selling shares.  Figure you what the price of each share is worth to yo to sell as an investment.

As well, if you have a solid business plan and/or an actual operating business, get in touch with some angel investors specific to that market, or hire an individual to begin selling your product or lots.  Hiring the individual for sales could be pure commission, which is the "finders fee"

Best of luck