Welcome to the world of NFA Suppressor - let me help you through the process.
Suppressors are rated for caliber and the pressure associated with them. Too small of a can on a large caliper and you will damage the can (ie a 22rimfire on a 300 WIN Mag - no go). Too large of a can on a small caliber and you won't get the suppression effect.
The quest of this game is to find the combination of caliber, ammo and can that gets you to hearing safe levels (less than 130-140db for firearms and impact noises). Pairing the right sub sonic ammo in the right firearm with the can and you can shoot without ear protection.
Quality cans will do one thing (suppress sound) without shifting your point of impact (POI). Cheap cans - may suppress the sound - but the engineering is typically weaker and blow by happens within the baffles and onto the round impacting the ballistics of your shot - on a 22 you can probably live with a minute or two of POI adjustment - that and you probably have that with the ammo itself. On a 300 WIN MAG or 6.5mm that you are trying to drop something at 300-400 yards - those minutes will add up and make you miss.
Some cans come with adapters (muzzle devices) (Dead Air Silencers) some don't (SilencerCo, SureFire, LLC) so there is some factoring in the pricing that we have to work thru. Some are direct thread - great if you only plan to use on single host - a time consuming pain if you plan to swap between rifles.
You're pricing on a rifle suppressor range from expensive +$1000- Surefire, Daniel Defense, Knight's Armament Company, Gemtech Silencer - to reasonable ($500-$800) Silencer Co, Griffin, Dead Air, Rugged Suppressors to Cheap Under ($300) - Rebel Silencers, Black Aces Tactical and about 10 other companies that start up a day.
Next - we factor in construction - materials of the can, the material of baffles, all welded, user serviceable - factory only serviceable etc.
Lastly - Weight and length - because a 6 oz can vs a 16oz can - makes a big deal on aiming and carrying a rifle. They both may function the same - but you might be willing to pay a little more of the lighter weight package.
How can we help? There is more - drop us a line of give us a call to help you navigate the NFA process.