Two weeks to get some 2-d artwork done

[Steel]

I'm part of a research group doing some public engagement at the science museum at the end of the month, and of course we've left it all a bit late. We have about two weeks to get some 2-d sprite art and background pictures for a little interactive game.

Does anyone know a good place to get some work done? We're looking to get stuff done quickly, reliably and at a not absurd price.

Also be handy to know what people think a reasonable price would be.