The way I see it, you can buy a Remington rifle, for the action. Then have it trued or "blueprinted" by a gunsmith, you then buy a new bolt and have a Sako style extractor fitted. Maybe you recoup some of your "investment" by selling the barrel, bolt and stock.
Or you can buy a custom action for just a little bit more. I do believe that a custom action from one of the recognized manufacturers will sell for more used than the accurized, blueprinted, Remington action. Either way it is not likely that one will sell either action for more than they put into it... unless it was they who blueprinted the Remington, and they don't factor in the cost of their time and labor.
After that it is apples to apples, oranges to oranges, comparison. If you want one of the less popular chamberings that are not offered by Remington in the barrel configuration you desire and twist rate necessary to stabilize bullets, you will be purchasing a custom barrel, whether for your blueprinted Remington, or for your custom action. Same for a stock... to get one you really like that fits you and your style of shooting.
So in the end I opted for a custom rifle built on a BAT action. There are Savage rifles with better shooters who will outshoot me every single time. But then I am only after my best performance, not so concerned about their best performance. And for me, ultimately, if I am not engaged in the activity, and enjoying myself, I'd just as soon go to work.
I reckon any time you shift away from a box stock rifle, you will rarely regain your "investment" whether it is a Remington with a custom barrel, or a BAT or Kelbly action. I do tend to see, among those who are likely to buy a custom action, a sort of dismissive attitude toward the blueprinted Remington action, and a reluctance to spend money on used ones, unless it is disassembled from the rifle and can be inspected etc., as nobody knows how good a job a run of the mill gunsmith did in the "blueprinting."
So, in sum, with my custom rifle I did not buy it with the thought in mind of resale, or of whether I was "getting a good deal" on the rifle. There is no doubt in my mind that if you put Taliv or Hoser behind a factory Remington for which he has loaded the ammunition, he will likely outshoot me and my custom rifle... but that doesn't really matter, to me.