Sometimes, you can get a decent price break on one on ebay. There was a guy offering one on ebay recently for 900 bucks...but that was with TEN complete caliber conversion kits, with dies, and in ten of the most popular calibers, no less! The dies and conversion kits alone were worth a thousand bucks!
Nobody bid on it. It may be up there again.
Search for "dillon" only in the sporting goods section, and you won't get anything but Dillon presses and reloading equipment.
Used 650's often go for near retail. But with their no BS lifetime warranty, there isn't any reason NOT to buy a used one. If it's worn slap out, just send it to Dillon and they'll give it what it needs and send it back.
I've got a 650 and it's fantastic.
Get the optional casefeeder. The machine is too fast NOT to use it. It's worth every penny.
Also, spring for the roller handle. It saves a lot of wear and tear on your hand.
There isn't an option available for the 650 that I wouldn't buy, come to think of it. Deck that sucker out, all the way!
CJ