Like anything else, it depends on how much it was used and taken care of.
I just had a 2 passenger ez-go with a lot of extras that I bought and sold several months later for $2600.....It was an electric.
A 4 passenger refurbished yamaha (2005) gas will run over $7,000 at TV golf cart shop. I know because I bought one a couple months ago.
The asking price is about what I have seen at the squares from private owners.