I have a used stainless Proof barrel, competition contour, for an Impact action I bought here on the Hide I’ve never installed I’d sell for $200. I think it has 400-ish rounds on and chambered by Permian Precision. I’ll need to verify round count from the ad, but that’s budget friendly if you want an Impact action. That’s half what I paid for it last year.
Shouldn’t be hard to find a local smith to mount, or you can do yourself easily with some simple tools.