My smith doesn't charge much at all, so for me, it's cheaper to get it all done than just the price of a new blank... So, we'll leave it at that. Haha But most folks will charge a fair bit for all that work. But it will make a factory barrel shoot nearly (and in some cases, just as good as) a top-tier aftermarket barrel, because at that point, you have done most of what is done to those aftermarket barrels that is NOT done to a factory barrel on a mass-produced rifle.
Those custom touches are what makes an aftermarket barrel higher-quality than most factory barrels. And a chunk of steel is a chunk of steel, and if the same processes are done to each, it should narrow the gap of performance significantly. Which has been my experience working-over factory Remington barrels and accurizing them.