Used? Depends on the previous use. If it was used only for gaming and kept within safe temps then it's still a great price for that GPU however if it was for mining then it may be problematic if it wasn't undervolted, ran hot and/or has a custom mining BIOS.
For a new card, that is a great deal.
The 580 8gb performs well at high settings in 1080p.
For used, that's a pretty decent deal for a well-kept card. If it is an ex-mining card, I wouldn't pay over $100 for it.