I just worked on a transaction with figures just below that, hovering around $530k (loan amount was about $450k) and the couple had credit scores of, gasp, 537 and 640, respectively (no joke). They brought about $100k to closing, so I think their incomes were what helped them, maybe think about that in your situation.
They were able to get a loan from a bank (they went through a mortgage broker who is fantastic!) and if you would like their contact info, just shoot me an email, and I would be glad to give it to you. Email: firstname.lastname@example.org
I look forward to hearing from you and Good Luck!