It's going to be a bit difficult to find one for that price (even used) as they're selling for considerably more on the second hand market (at least in the UK).
I'd say your best bet is to go for a Phantom as per Blazed's offer. Alternatively, depending on what you need it for, you could get their newly released Spark for $500 (it ships June 15th). Not quite like the Mavic in terms of functionality but it's pretty neat as a personal drone.
I'm looking for something portable and still shoots high quality videos. The mavic pro is the best choice IMO. I'm thinking about the spark, but it seems that the mavic shoots significantly better videos.