A scout mount might work for you- they usually cost around $75 for a decent one, and are easy to install- remove the rear sight leaf, and attach the mount to the rear sight base. You'll need a pistol or shotgun type long eye relief scope. No drilling/ tapping required.
Something to think about when mounting a scope to an old mauser get the rifle appraised before drilling/tapping for a scope- you might be turning a $1000 rifle into a $100 rifle in a minute's time if the rifle is in original condition when the drill hits the receiver.
S&K makes about the best scout mounts for mausers.
http://www.scopemounts.com/index.html?instaprice.html