I have a Mitchell's K98 that my Dad gave me as a gift several years ago. I shudder to think what he paid for it (around $500 if I recall what their ads looked like back then) for a 1939 German K98. I looked up the marks on it once but forgot where in Germany it was made, but it was a German one. The stock was heavily re-done, sanded and maybe stained again, I'm not sure. The stock is beautiful, and the rifle seemed to be in good shape. That's great for me since I collect shooters, not display items. However, whatever re-finishing Mitchell's does probably ruins the collector's value of these rifles.
Now, I also have a C&R license and it pains me to see that similar German K98s probably go for a dealer price (even today) for somewhere around $250-$300. They would need some finish work maybe, especially on the stock. But, I know my Dad enjoyed getting it for me and therefore I do enjoy taking it out every once in a while and shooting it. If you want a K98 (or a Yugo M48, or a Czech Mauser, or whatever) though, I recommend being thriftier than buying a Mitchell's Mauser. Spend $30 to get yourself the C&R license, and buy yourself a Mauser from any one of the dealers who sell these things. Hell, your local FFL will charge you at least $30 just to transfer that $500 Mitchell's Mauser to you anyway. Get your C&R (FFL03) and any dealer can ship it straight to you since you're an FFL (03) and it'll cost you half of what the Mitchell's would cost, even including the $30 C&R license.
Ammo: I could kick myself for not buying more of that Romanian 8mm Mauser surplus ammo back when it was about $0.15 per round, back in early 2007. That's maybe half of what the cheapest Romanian 8mm costs these days, and of course there's not likely to be much more of it found and sold.www.aimsurplus.com
(for the ammo, and every once in a while they have K98s). I think Classicarms.us also has some.