Actually 250 on a suppressor and 20 bucks for a new baffle if one goes bad. If you read through you will see they have a replacement process.
And aluminium is used on a ton of suppressors that cost a LOT more. Will they handle full auto abuse, no but for a cheap device I think they will do pretty well for a 22 or 300 BLK build.
Its fine on a 22 lr or subsonic 300blk or pistol cartridge. Just not 223 or 308 full power loads. If they just pressed in a stainless or inconel liner in the first piece it would make a huge difference. At least they put in a stainless thread liner so hopefully it doesn't blow off the end of the gun.