What do you mean??? It's only and upper swap.
If only it were just an upper swap.
Radical firearms upper, $240 plus freight, on sale right now. I don't think one can be built for less unless an absolute bottom-dollar barrel and handguard is used, and the receiver bought on sale.
BUT.....
Scope base, $50 minimum, QD mount more likely, nearly as much as the upper.
Scope, if he buys one just for this upper, could be anything from $150 on up.
Brass, he'll probably do what I did and buy it because he's probably as sick of cutting cases and turning necks as I am. $65-100, depending.
Reloading dies, at least $45, if he's smart he'll get a Forster seating die too, $50, if he's even smarter, which I think he is, he'll just make one.
I think the 30 Sil mould will be bueno for starters, so no up-front investment there. He's got a shellholder and can easily make an expander die (note Brad, if you do, make the tip of the spud very long and pointy 'cuz those little cases wobble all over the place and the mouths get crunched).
Finally being able to chamber the AR-15 in a caliber that makes absolute sense on so many levels......PRICELESS.