Here are the prices for that stuff new.
Bow - $650
Sight - $100
Rest - $45 - $65 depending on if it's a 2000 or 4000 model
Stabilizer - $45
arrows - $60
Peep, loop - $15
Limb savers - came on the bow.
Total is almost a thousand bucks. Typically used bows sell for about half of what they cost new. I would try to get to about $500.
I assume you are looking at the one on ebay.
http://cgi.ebay.com/HOYT-X-TEC-LOADED_W0QQitemZ7176259995QQcategoryZ111250QQssPag eNameZWDVWQQrdZ1QQcmdZViewItem
I would not pay $600 for that bow. Especially with no pics.