You may be “hosed” by simple checkbook analysis. But you’re quite a bit less hosed than the people who bought at the top of the market … and it seems there are quite a few of them.
And while there are a number of 2500+ sf houses on the market for less than $300K, trashed REOs and other brown-lawn specials seem to be overrepresented, at least from what I’ve seen on Redfin.
You have a house that you like, and it’s within your means. Please. Be happy.