Alot of Bally 6803 games are under $1,000 and you get some pretty cool original themes there.
+1 if you can find a System 11 for $1,000. That's not always an easy task.
Some System 3 Gottliebs can be had for $1,000 like Shaq, Street Fighter 2, Big Hurt, Wipe Out. DMD - Deeper Rules and really reliable board sets.