11%! That sounds like B or C paper. That or you are buying something like a condo, or other 'high-risk' mortgage.
Remember those rock bottom rates are for good credit. The more problems, and the more recent, the higher the risk, hence the higher rate. Also, the more you put down, the safer the risk to the bank/mtg lender, so a better rate.
At that rate, and amount, you should look into getting the seller to finance.