Quality declined in those pre-64s made after WW2, apparantly:

http://www.fieldandstream.com/photos/gallery/kentucky/2007/09/50-best-guns-ever-made

Maybe check on the "usedguns" site to guage value?

It may be a long time before an original one of these would be worth significant money, and it would likely have to be in pristine condition too.

If you look at ex-military firearms as a comparison, it only the very uncommon ones (ie not produced in high numbers) in "good nick" that fetch ridiculous prices. An excellent "common" exmilitary mauser will be in the order of $1,500 - $2,000, which would be under-value considering what it would cost to built something of the same quality these days.