Depends on the pedals, and condition of the pedals. Cheap SPD's aren't too reliable for serious backpedaling/skidding. Can't go wrong with the Time ATAC's.

Depending on what kind of pedals (2 or 3 bolt mounting pattern), the shoes can be had pretty cheap. I like the bottom of the line Shimano MTB style shoes, which work with 2 bolt pattern cleats (SPD/Time ATAC/Eggbeaters/a few others). Cost me $60 at REI, plus the cleats.