You can't do it directly. It's a foreclosure and the bank wants cash.
What you do is find an investor to buy it for cash. Then the investor sells it to you on terms.
Example: Investor buys it for $20,000. Let's say he/she is able to buy it for all cash.
The investor sells it to you on these terms: Purchase price $30,000. $5,000 down. 12% mortgage for 15 years. Your payment: principle and interest come to $300. That should leave enough to pay any property taxes.
If you don't have $5,000 to put down, the numbers on $3,000 are similar: 12% mortgage for 15 years works out to monthly payments of $355, still well below your $400 maximum.
There are a huge number of real estate investors in your area. A Realtor who works with investors should know plenty, including some willing to fund your deal.
Hope that helps.