Prices are all over the map. I bought a M&P (4th Change) last year that was finish-challenged but was mechanically in very good condition. That was a $200 gun.

Very early ones might be best shot with light loads, as their cylinders were not heat-treated. The ones made before about the middle of WW2 may not be drop-safe. As I recall, S&W made an engineering change after a sailor dropped his revolver and it fired, killing him.

If you're new to buying used revolvers, guidance can be found elsewhere on how to inspect them to lessen the chances of buying a trip to your local Smith smith.