Finding a nice working game as described should not be a problem if you are buying from another collector. Retailers have a different model and are selling games to a buyer that may not be interested in ever getting there hands dirty.

Being a newbie, I strongly recommend you buying a working game in person after spending time playing the game and liking it. Pinball shows are a great place to do this. Most of the games in the free play area will be for sale. Don't worry you will have plenty of opportunities learning repair and restoration skills as the owner of any pinball machine over 25 years old. You should start with your head above water for that first game and focus on keeping it working.