The difference is price is from high quality wads (flight control is hard to beat) and composition of the shot. Basic buckshot uses unplated soft lead shot. The patterns can be erratic because the shot get severly deformed when fired. Hard shot improves patterning. Copper plated or even nickle plated shot is best as the shot remains very round when fired. The difference between soft shot-fiber wads and plated shot and patten control wads is night and day. The difference can be 50% better patterns and 2X the price. They can make the difference between 100% hits in a HD situation and one or more fliers bouncing around inside your home.
In life, strive to take the high road....It offers a better field of fire.
"Robo is right" Fuzzball