Unless you swap scopes quite often, or buy a lot of new rifles that need set up, don't bother buying a bore-sighter.
Most combinations bases/rings/scopes will get you on the paper at 25yds. If not, you might have a problem.
Fire a shot (or three) and adjust accordingly. You should be able to have it dialed in with very few shots. 22lr is CHEAP...you'd have to sight in 50+ 22lr's using a bore sighter before you would save money over "wasting" ammo.