Don't let the R5 rifling guide your decision either way. It's not that big or a deal. Cut rifling, air gauged and hand lapped if button rifled are much more important. As one member mentioned above you could build a new rifle with a match barrel for about the same price. Just buy any used or new Savage short action rifle with a nice HS stock and throw on a Shilen SS Select Match barrel from Northland and you'll shoot .25-.5 MOA groups all day long if you take the time to work up a load for it. You'd probably get $100-$150 for the factory barrel on this forum.

Not sure if you need or even want a muzzle brake on a .308. That scope is $800 brand new, so still $600-$650 max used. If your heart is set on this exact rifle, I'd still spend a couple hundred more and buy brand new. I know Bushnell will require the original receipt for any warranty issues.