How to counter a seller financing counter offer?

[Account Closed]

I made an offer on a multi, which included 93% seller financing. I offered full asking price ($400,000). COC = 17.2%. Seller countered saying he will finance 50% (COC = 7%). This all done without ever meeting face to face. I'm very excited because that alone is a heck of a feat. Here is the problem: I don't know where to even begin countering.

If I was going to put down $200K, I'd put it down on an $700-$800K deal, which would be almost double the units, with a commercial loan.

 I'm not sure yet, the seller's motivation for the 50% down counter, probably just a trust thing....I will try to find out. Any ideas on where to go from here?