20k non refundable escrow

[Connor Wingfield]

To make a long story short, I am an architect that has been doing work for a flipper in LA. I've been presented with a deal to buy one of his deals at a price that seems way under market. This would be my first flip where I would be buying. I have been hustling to find figure out the financing, and found the best option with Patch of Land, who are a sort of hybrid HML and social financing company. They have given me the OK to move forward, saying in an email and verbally that they will offer purchase and rehab money.

As soon as I went back to the seller with my he explained that he needs a 20k non refundable escrow /  earnest deposit. His concern is that if we go into escrow with out this the and the lender is decides after their appraisal and or anything else  he is going to loose out on time/money. 

The lender is OK doing the appraisal prior to escrow but still unable to tell me the probability of closing at this point. I was wondering if anyone else has been in this situation and or if any one can shed light on what other issues I should be concerned about with a lender not being able to close. Also any issues to be concerned about with a non refundable escrow?

Thank you!