Disposable is probably not the best term. Use, wash, sell...repeat. I am on my 2nd RAP in .243Win and I will likely sell it this spring. About 5K on the All weather RA in .223 I use as a trainer for new shooters. My first one, it cost me $75 to put 2K through it. Sold it to a guy who is going to shoot a box a year at Deer and Pronghorn.
I have had three completely apart. One a RAP and the other a RA all weather and a RPR. What I found was consistent with what others who have trued up their RPRs. Bolt lugs and faces, some in the barrel locking lugs as well. I guess the nice thing is that they can really be squared up and polished up at home, if one wants to, since headspace is easy to reset.
From a $ per round with decent accuracy, the Rugers are, for me, a great value. Even as a high volume shooter, I have to balance the time I spend reloading, shooting and working on guns. For me, it takes about 30 minutes of time to sell one and get another. So it is 1/3rd the time and cost to sell and replace as to true up and rebarrel. I'll use that time on my higher priced rifles though, and those are what I mostly shoot in matches.