How much do automatic garage door openers cost?

[CTyankee]

We have one that is at least as old as we've had the house (22 years) but I don't know when it was bought. It's in pretty good condition but often "stutters." That could be a fault with the "starter" button or whatever you call it. Sometimes I can't get the remote to work either. Would it pay just to replace those two items and paint the front and back? We won't be in this house much longer than another year or so...