If you are talking about the portuguese military mauser rifle, I very much like them. The sights fited to the 8mm conversions were one of the best I have seen on a military rifle, and beter for me than most standard comercial sights. I find the action to be extremely smooth and fast, rivaling the lee enfield. I find it better than many comercial actions in that regard. the drop floor magazine is also a nice touch, stops you needing to cycle rounds through too empty it.
Many people tell me that these rifles are not as good as the 98 mauser, but I would disagree. The strength is suposedly down from the 98 mauser, but I don't know where this would become important unless you want to grosly overload it or try for a magnum conversion. The split rear bridge apparently makes scope mounting difficult. This is not an issue to me as I mostly use open sighted firearms, with just a few scoped for sniping rather than hunting. Not a critisism of others, just my preferance, and I may change that view now my eyes are getting tired.

The original calibre was 6.5mm, with a 58mm case length, but I have never seen one in that calibre. I believe they were all officialy converted to 8mm by the portuguese many years ago.
As to price, I remeber them being sold in Australia for $35 each, complete with bayonet and leather sling, all in very good to excelent condition. Wish I had bought a stack of them, although later events would have destroyed them anyway. I know some "custom" makers here bought them just for the floor plates, throwing the rest away. Sad waste.