Not easy to make suggestions on so little info. Those Spanish Mausers range from good condition with decent barrels to absolute junk and "sewer pipe" barrels. If the gun is in decent condtion, it is well worth $99.
But if the intent is just to buy something cheap and "fix it up", best forget about it. "Fixing up" a junker is never a good idea and tends to be a "black hole" for money.