adapters are $150
mags $25 (him modding & testing)
barrel is $225 any length
thats the only real prices he has set..
all in all? ive got less than $600 in this.
some people will big eye that number...
but this IS a gas operated upper... NOT blowback.
45acp uppers are over $1K
TOK uppers are right at $1K
9mm uppers at about $650
so this is actually a decently priced custom upper.