Hi,
I recently had a 1970's Mauser Parabellum in .30 luger refitted with a fresh barrel, after a reloading mishap. Bought it in this damaged state (with bulged barrel) from the first owner. Found an original factory barrel (which was a bit of a challenge in itself) and had it refitted and reproofed in Germany. As this was all meant as a project and very much labour of love by those who worked on it, the cost was reasonable (300-ish euro), but not cheap. If done completely commercially, costs would have grown above the 500 euro mark...
I guess refitting an original P08 is actually easier than reworking a post-war one, but I would only buy one as a bit of a project, not as an economical solution. Usually the finished product costs more than a decent, working shooter.
But then again, I like to see things come back to live again. Part of the fun and a bit of a sentimental side of me I guess