I have 2 Mauser K98k. By no means am I any kind of an authority on them, but here is what I know.
Matching number 98ks are pretty expensive. If you are not a real collector there is no reason to be concerned about that.
There are a lot of Russian capture RC 98ks available. Both of mine at RCs. The condition of them varies from very good to pretty poor. The critical thing is the bore. You can work around everything else. Gunbroker.com usually has some. You shouldn't be paying more than $350 for one. I would try gunshops, pawn shops, and gunshows. Mitchels actually had pretty decent 98ks, but the remainder are supposedly getting to the lesser ones as they run out. The beef against Mitchels was that there were accusations that they "force" matched parts - restamped. The Yugos were very good condition. I just prefer the standard German 98ks. The wood is more delicate and streamlined looking compared to the humped Yugos. The actual quality of the wood is better on the Yugos - although the laminated German stocks are actually better. Most RCs have the Nazi markings peened out. So if you want one undamged with Eagles and swastikas, you have to search a bit. The different factories had some differences in stamping. Not a biggie. I got one of mine because I liked the way they scrolled some of the stamping.
The Belgian and Israeli reissues in 7.62 are harder to come by and generally cost a bit more. But I agree with Paul that it is nice to have them in the modern caliber. I have one of the Czech vz.24 (Czech Mauser 98k) that has been rebarreled to 7.62. Wanted it because of the modern cartridge and because of my Czech ancestry. However, the old German 8mm Mauser is slightly larger and longer than 7.62, so the ejection requires some real work to get to work correctly on a slow extraction. A hard fast extraction works fine, but a slow doesn't.
The 98ks are men's rifles. Powerful kick. Mainly iron sights. Scoping is a little more difficult. As for the basics, Mauser created a masterpiece that stands the test of time. There really isnt a significant step in the design and function over the Mauser. Hard to improve on it.
When I get home tonight, I will post pictures.
Here are my two 98ks.
and the Czech VZ.24
Here is what I mean about markings. You can see the undamaged original stampings and the scroll.
The Russians varnished them with a reddish varnish. Finish looks pretty bad. I left one original and redid one.
Looks different now.
Every Mauser 98k I have ever shot shoots high. Had to do a small build-up on the front sight post that can easily be removed for back to original. Wanted to scope it without drilling holes in the receiver. Got another of the sight beds and used it to rig on a scout scope.
Here it is next to my buddies Yugo.
The way I did the scout scope (long eye relief 2x7 variable mag) means I can remove it with no damage to the rifle.
Sorry I dont have any targets. It shoots well, but isn't a tack driver.
Unless you want the Mauser just because you want it, you are better off going Remington 700 in the caliber of your choice.
Now the VZ.24 is a tack driver.