Referral Fees for non agents

[Vonecia Holbert]

Hi there,  I am new to real estate investing and i have a situation in which im not to sure of.  A fellow investor reached out to me about a house they have under contract to wholesale. They don't have a buyer interested in the area but i do have a buyer. My question is if I connect the investor with my buyer how much would i charge as a referral fee?  Or what is the standard referral fee for a non agent?

Thanks for your help

Vonecia