As a gunsmith and a former barrel maker I think I can answer your question.
#1 is the basic principal of building anything in business which is this;
Everything is about overhead, materials and labor

In making a barrel you have steel and machine time as well as some hand lapping
In a re-bore you have all the same things except the steel.

Ordnance steel today is selling for about $6 a pound so if your barrel has 3 pounds of steel in it, the steel is worth 18 dollars and ALL the rest of the cost is machine time and labor.
But in a re-bore you do not have the luxury of making the barrel long and cutting off the muzzle end to eliminate run-out of the tool head, which is how all cut barrels are done. So on a re-bore you have MORE set up and labor that can far exceed the $18 it would cost to start over.

The point is this;
Is there some reason you want to re-bore instead of replace?
In restoration work we often want to re-bore or re-line because of some historical significance.

Or if you have a barrel that is machined in a fancy way, ie. having a integral sight or rib, of some such other feature that you do not want to loose?

If not you will be FAR better off to re-barrel the rifle then to re-bore, re-chamber and re-rifle it.

So, please tell us about the rifle. WHAT DO YOU HAVE?