In Palm Beach County, Fla., buyers who find fire-sale bargains at foreclosed home auctions picking up, say, $400,000 houses for $100,000 or less are also realizing they’re required in many cases to pay the same property taxes, as if the homes were still valued at $400,000. In Miami-Dade County to the south, where one in four homeowners are 30 days or more behind in their mortgage payments, residents are bracing for what Mayor Carlos Alvarez says could be an imminent property tax hike to fill an almost $400 million budget hole a move that veteran Miami realtors like Alex Shay insist would set recovery back.