I bought a used eu2000i on eBay from a equipment rental place for about $550. eBay user was "vanrent". Generator is in perfect working order. Was maintained well.
If you're looking for an inverter type 2000 watt generator check out Costco. I had the Yamaha EF2000is, It's awesome but expensive, about a grand new. Costco had a 2000 watt inverter generator that was using the Yamaha motor. It looked just like my EF2000is but it was red in color and it color and it was only $599. If I didn't have my EF2000is I would buy that one. If you don't like it Costco will take it back. Everything was the same from the Costco one to my Yamaha all the buttons and knobs are in the same locations.