Looking at IBI's prices, a barrel nut prefit is competitive with a blank plus gunsmithing. I very much doubt that the quality of the basic barrel is any different. Might gunsmith installation be superior? Maybe, maybe not. If you can do a barrel nut installation yourself, it might make sense. If you are already set up to do the machining yourself, starting with a blank would be less expensive.
Most "at home" smiths don't have taper attachments for their lathes. This can make the process tedious at best.
The other issue most "at home" smiths don't have auto cooling lubricant on their cutting tools while turning down the barrels.
This isn't an issue if the smith has the patience to make small cuts and allow things to cool between cuts to ambient temperature.
Other things, like half rest adjustments and placing the half rest in the proper location on the barrel, are also needed.
Then comes another issue, "real working length" on the bed between centers.
People can go on and on about offsetting the tail stock for the proper taper, but for those doing it regularly, it's best done when the barrel is turned between centers, using a "dog leg" attachment to hold the barrel, with the "leg" inserted into a slot on the back plate.
I haven't tried one of the "Remage" type barrels, but I will be ordering one in the morning from JC Custom Barrels, out of New Brunswick.
I don't have a 280AI reamer, don't want to be bothered with the tedious chore of profiling a barrel, then fluting it, although I have the tooling.
The cost of this custom stainless barrel, with fluting, chambering, choice of twist, length, and rifling profile, as well as the retaining nut, is about the same cost as it would be for a similar grade blank, and I don't have to purchase another reamer for a one off job.
I helped a friend swap out a barrel on a Savage. The threads were snug all the way to the lock up point where the jam nut was snugged up to the receiver. When this happened, there wasn't any noticeable movement. We did it all in the lathe to keep everything true during assembly/lock up.
The completed rifle shot quite well. It was barreled with a 308 Palma, precut chamber. MOA or less groups at 100 yds are the norm with this rifle, with good Hirtenberger surplus ammo. Sub moa groups are the norm with his hand loads.
The barrel came from a different maker, but JC has a good name, and I'm going to try one out.
I know JC isn't a banner advertiser, so you can remove this if it offends anyone, but he is a Canadian barrel maker and his prices are very competitive.
After I get the barrel and install it, I will come back with a report, if I remember.