A light contour barrel, such as comes with most hunting rifles, will not take the heat and maintain dialed in accuracy for repetitive shooting. These barrels will "walk". POI will change and grouping will open up as barrel heats up.
In my experience factory barrel take off's, even new unused ones, have little to no value when it comes to trying to sell them.
Factory recievers that have been blue printed and trued cost near as much as buying an aftermarket billet reciever such as Surgeons, GAP, Pierce, BAT, etc..
The down fall of spending money on blueprinting and trueing a factory reciever is that if you ever want to sell the rifle it will be worth no more than any other rifle with a stock factory reciever.
A Remington 700 reciever that has been tured and blueprinted and a bull barrel added to the mix (such as a Krieger #9 MTU) with a good trigger such as a Jewell, and a use specific stock will kick arse in most competitions. However, you will have alot of $$$ tied up in it that you would never be able to come close to recover if you decided to sell.
Now most of these aftermarket bolt action recievers are externally patterned like a Remington 700 reciever as more stocks, triggers, DBM's, etc.. are available for the Remington 700. With one of these recievers you'll be within a couple of hundred or so $$$ over a trued and blueprinted factory 700 reciever and if you ever decided to sell you'll usually get not much less than the $$$ you originally put into it.
Depending on the caliber you go with, barrels will have to be changed out every so often to maintain good persicion. A .243 or or .300 Win. Mag., for example, have relitively short barrel life for percision compaired to some other calibers.
Just my 2 cents worth here with my limited experience.