Suppressors are very expensive here. In addition to the cost of the suppressor, I have to pay a $200 tax for each one, and a 6% sales tax. The paperwork takes about 90 days to be processed before I can bring one home. Most people don't even know it's legal to own them here.
Advanced Armament's suppressors are medium priced. I have a couple that were way more expensive, and a few that were lower in price.
I have no idea how different the effectiveness of the suppressors you have and the ones here would be. There may be no difference at all. I have an integrally suppressed .22 bolt action rifle, and the loudest sound when firing it is the sound of the firing pin hitting the rim of the case. The loudest sound when firing my suppressed semi-auto .22 rifle is the bolt hitting the bolt stop as it ejects the empty case. My best 9mm suppressor is good enough that you hear the slide cycle on the pistol when you fire it. And that's with full power 147 grain ammo intended for submachine gun use. Just barely subsonic from my pistol barrel.
The guy who did the work on the Kadet on the website is named Kevin. He's at the SHOT show right now. When he gets back, I'll ask him how he attached the suppressor to the one on the website, and I'll pass that information on to you here. It may be of some use to you.