The VERY few DMDs worth owning in the sub 1200 mark would be Tee'd Off and Cue Ball Wizard (if you can even find them for that price anymore?)
I would say any Bally 6083, sys11, or gottlieb sys80/80B are all solid choices.
Reality is ANY tuned up solid state for 1k is a good thing for a beginner. Find a decent title that someone else has already gone over and then he will have something hopefully pretty reliable to play.
Quoted from danczaz:Bally Atlantis
Still completely amazes me that Atlantis can still be found in the 1200 range.
If your buddy can find one (pretty rare title) then tell him to jump on it. Great game play, great art, great sounds, challenging play like a sys11, and just all around fun. I mean whom does not like hot chicks riding dolphins?