Note: I do not want a fixed gear, but flip-flop will suffice.

I need a set of cheap wheels for a bike that I'm building for my wife since her's was stolen.

I was going to do a complete bike build, but if I go with a single cog, all I need is a single brake caliper to complete the build (horizontal dropouts).

I'm in CONUS.

The cheaper the better; as long as they're not taco'd.