Tooling in my occupation (pharma tablets) has to be machined out of high grade tool steel to tolerances just as tight as a suppressor then put through heat treatment and QC. Each punch is less than $80 FOB.
They're expensive for your first reason, because they can charge that much. It's a prime example of over zealous government regulation allowing for artificial markets.
Some stores like SilencerShop run promos from time to time where they will pay the $200 for the stamp if you buy from them.
¥ The origin of your right to keep and bear arms ¥
I have a 7.62 can in tax stamp jail at my local GS, when I was shopping I found E-silencers had the lowest web price on the one I was shopping for. I never used them because my local store was within 30$ but it's somewhere to check.
Florida CWFL Member NRA , Florida Carry