I've managed up to 400 rentals and never offered a concession.

What I am trying to better understand is at what pointy that restaurant owner able to either delegate or reposition so he / she doesn’t have to the restaurant every day. do they need to obtain more restaurants or keep offering more to their current customers?

So, you, as an individual, may not get to the same rate that a MASSIVE national builder can...but you can certainly offer credits to the buyers to help buy down the rates. 

This is my gamble.

A big question is do you have the $25,000 to gamble?

So in reality you are ALWAYS gambling in the stock market, yes, even with those big names that seem inconceivable to every drop and ESPECIALLY with those because most are so shocked and in disbelief when it occurs that it's only realized after your left with pennies on the dollar because you waited out a recovery that was never coming. 3rd: MATH and leverage.     

They would offer a more hands free approach, but eat up the profit in return.

If you’re offering $450K, then you could offer to take over the $120K payments and seller finance the remaining $330K.

I plan to offer owner financing to others that can't get a loan.

Boone Pickens got involved and offers were made on the remaining portfolio.