My first deal, question about earnest money

Hello everyone, love this site. I'm proof up by my lender to do my first investor so I'm the exit buyer, and my best friend found a great deal at $22/sqft on a home that's 4000 sqft of living space, and place the home under contract with an option to assign. My lender now wants $400 for an appraisal to be done but also wants $1000 as earnest money. I get the $400 for an appraisal but shouldn't my best friend who is asking 10k for his assignment fee be the one to determine the earnest money or is it the original seller, certainly not my lender am I correct? I was told earnest money can be as little as a dollar to make the deal binding, I like to give$100 instead. Need help ASAP, don't want to see this deal slip through my fingers.

Thanks,

Abel