Option A) rent. Then once you figure out if you want to get serious, find a pro shop in the area and see what used markers they have.
Option B) craigslist as Ns1 suggested.
Option C) goto Walmart/Dicks and buy a crappy "kit" for that price. Expect the marker to not be that great and have issues with it. Also expect your mask to fog.
I did Option A, then bought a great used Shocker that was owned by a pro player on the shops team. Great marker, have not had any serious issues. Only two issues I've had with it were a blown o-ring in the marker (took 10 min or so to fix) last time I played, and the compressed air tank needed a new regulator (which sat me out about 30 min while they put a new reg on it).
edit: keep in mind that you may/may not be able to buy upgrades to the stock barrel, air system, electronics (if it has em), etc if you buy a kit in this range. So IMO you should try to rent first, then figure out if you actually want to sink money into it or not. Its a great sport, extremely fun, but can get expensive quickly (so far I am in the $1300 range for all my gear).