Help with JV terms on a multifamily deal

[Account Closed]

OK I have an investor wanting to JV on a multifamily portfolio (6 houses), he will provide half of the down payment and find a line of credit for me on the other half. In return he wants a 50/50 split and wants me to convince the seller to "carry-back" 40% and not the current 70%... (the seller is financing and currently if a 150000 down payment is made, the seller is financing the difference of the asking price of 535k which means he carries back 385k. Is this investor asking if the seller will lower the asking price and only finance 214000? (40%) Or do I have this wrong?

I'm doing some research now but perhaps someone could shed light on the importance of carry-back percentages?