I don't think this collateral would protect the lender very much. If your bet ends up being a loosing bet then it would essentially be a collateral free loan.
The question of if a collateral free loan is appropriate given your prior trade history is up to the free market.
that's true that if they lose, than my collateral is only worth .2 btc. on the other hand i won't accept a loan from just any non trust worthy lender as well, since it's more than likely to be worth 2.6btc.
i can also add to protect the lender then, that i can do the online xfer of boa of $200 upfront. this obviously only helps if they have bank of america.
lastly, wanted to add that if i don't get this loan fulfilled in the next couple hours then void this loan request. obviously the closer it get's to nfl sunday, then the less and less valuable the btc becomes to me. and after nfl sunday, then i may just end up buying btc if they lose.