Its a cylinder with baffles that can withstand tens of thousands of rounds. Some handle extended FA.
Generally the more you pay- the less poi shift, and more durable.
That translates to material cost and machineing cost. You can make a silencer with decent sound performance for less than $100. It wont last long and poi will suck.
Figure out what you want and find what price-point that brings you to. Yhm newer stuff looks good for general purpose stuff for cheap. I went SF and recommend them if it fits your needs.