Only barrel I ever broke in was the $249 Vanguard I bought last year. Did it to avoid warranty issues in case of accuracy problems, and maybe just to gave the experience. Boring!
My two favorite writers disagree on this. JB seems to think it's unnecessary; Brian Pearce seems to do it quite a bit, and from his articles, I'd say that it at least may speed up the break-in that ordinarily occurs with normal use.
Take your pick. As a lazy old fat man, I'm siding with Mule Deer, unless the maker if an expensive rifle insists on it as part of their warranty. Thankfully, Barrett doesn't.
