My first (and currently only) pin is Hollywood Heat, which hasn't been mentioned yet. I paid $1000 Canadian for it (a little over $900 USD at the time of sale), which is actually a little more than most people would pay for that game, but then I bought it as a closeout from a distributor leaving the arcade gaming business and it was in decent (though not perfect) shape.
Hollywood Heat is a very simple and easy game with an unusual playfield layout and a gaudy Miami Vice styled theme, but also has some catchy retro synth music, an alphanumeric display, and a 3-ball multiball feature. It usually doesn't stick in people's collections, but it actually makes for a good "first" pin due to how little it goes for and how much you get for what you pay. In less than perfect shape they can be had for under $800, and even in perfect shape it's typically not much higher than $1000. : )
Of course, anyone planning to buy their first pin needs to have played a bunch of different ones so they have an idea of what kind of features they want out of their game. What kinds of features does your buddy want? We might be able to narrow down the selection for him. ; )