Mr. Trooper that is not entirely true. I have had 98s sporterized but haven't ever sold one. However, I know people that have had 98s sporterized by reputable gun smiths that have sold them for good money. Also, your vision of a sporter Mauser may be clouded because you cannot do a quality job for $300-$500. No Way. Just fitting a new barrel will cost that much. Then having the bolt bent, drilling and tapping the receiver for scope mounts, a sporter trigger and safety, and bluing is going to run it up to almost a thousand. They aren't cheap. But you can't buy a finer rifle for what you will pay to build one. If you get a good clean action and put a decent barrel on it, you will have a shooter that feels like a real custom rifle, which it will be.
I am having a Yugo 24/47 rebarreled to .257 Roberts Acley Improved. My gun smith is bending the bolt and drilling and tapping it for scope bases, adding a Timney sporter trigger and a Winchester Model 70 3 position swing safety, and screwing on a Shilen 26 inch Stainless medium sporter barrel, and installing a Leupold Side Focus 4.5-14x56mm VX-3L scope with 30mm tube. I'll have almost $2,000 in this build. It is my most expensive build to date. But it's something I always wanted and wanted a 98 Mauser action, which a Yugo is actually. The Yugo is about 1/4th inch shorter than a k98 or similar Mauser, making it ideal for the 57mm case of which the .257 Roberts is built upon and also which the 7mmx57 is (it's actually the parent cartridge) and also the 8x57. Also, the 6mm Remington is built on this case. Anyway, this is something I have planned for and been waiting for the right opportunity.
So don't sell the Mauser action short. It may cost a little more, but it builds an excellent rifle of which if it's done right will sell for more money.
Edited to Add: However I would not advise building a rifle on a small ring action because it is not as strong as a 98 style. Yugos, K98s, and several more are large ring 98 actions and it would be adviseable to build a rifle on one of those. As stated, the small ring isn't strong enough for modern high pressure cartridges such as the .308 Win.