I have ones that came with my Truvativ cranks, 32t and bashguard.
As for price... hrm, I dunno, let me see what they're worth new so I can assess what they'd be worth 2nd hand.
They're in good condition, obviously the ring isn't bent, the bashguard has a few minor scuffs as you'd expect, but it hasn't taken any big impacts, and the chainring still has plenty of life in it before it'd be considered worn...