Sounds like they could have different PPP or fees that go along with refinancing with a different lender. 

If what you say is true, I know my base fee would be roughly half or a third of that for your situation if that helps to give you perspective.To speak to the other posts in reply to mine, I appreciate the clarification.

You should be able to build this into your cleaning fee. 

Are there any lenders or ways to finance the entry fee for subject to deals?

If it's in your name you can look into the potential for a HELOC or potentially refinance to pull out some of the equity you've created, but you'll need to do the math to see if you're payments will increase based on the new loan terms.

Additional Fees. 

I think it only makes sense to switch if your current lender is not meeting your expectations, and the rate/fees are significantly different.

On the renewal for the license, I asked if the loft was considered a bedroom and the response I got (unsurprising when it comes to taxes & fees!)

Perhaps in return they collect an acquisition fee,  collect a construction management fee & share in a portion of the upside.

But it should only be attorney cost, the deed and recording fees (few hundred) , maybe a final water cert.