(The fees don't help - that you are correct on) But having the nanny state interfere in your own personal investment is more than a lot of homeowners are willing to concede.

Buyer almost backed out; the seller had to concede a lot to get the buyer on-board with the only 30YF jumbo lender that would go for the scenario. 

Of course that's not true, and with the right education and preparation, anyone can succeed.Now, one thing that you have to concede is that real estate investing involves risk.

Concede to the tenant request and next month you could be slapped with a lawsuit for Non-Habitability

I've conceded and plan to buy a single family soon.

I concede that its reliability is highly questionable since I found it randomly on the internet, but here it is.  

Be willing to concede one or more in order to cement the deal.To answer your question, yes you can still negotiate the price, but you need to be prepared for the owner to say they aren't willing to do owner financing unless they get a higher price.  

Ok, I concede that it is possible that they did accept another slightly higher offer with an inspection contingency and the buyer later nenegotiated..if they did the listing broker is an idiot.

Why is the seller so willing to concede on both down payment and interest rate? 

If they do not concede enough I walk.