Quoted from Blackbeard:
Right now, for around 1k, you can mayybe get a big guns, which is a blast to play. Road kings, millionaire.. all around that figure. Maybe more towards 1500.
Also, look at something like a Flash or gorgar. Sometimes you can find one on the cheaper side.. or firepower.
1K for a Big Guns? "I'LL TAKE 3 AT THAT PRICE", etc.
It depends how "around" 1K you want to be and what features you want. The cheaper System 11 games like Millionare are out there like Blackbeard said...but keep in mind there is a reason that they are cheap. Not necessarily great players (all subjective of course) and hard to sell down the road. With 1k you are likely pretty pigeonholed into early solid state games like Flash, Meteor, etc. such as what was posted above if you want a fully working game. You can get some great EM games under 1K if you are into those.
If you are looking for something more like a Taxi, especially working, you'll probably need to stumble on a deal on FB, CL, etc and hope you're the first guy there with cash.
Try going though the Ohio thread here or check out some of the Ohio FB groups. There is a pretty large collector community in Ohio, especially around Cleveland, and I have seen some games on FB like Space Shuttle and High Speed sell for $1400ish in the past 2 or 3 months.