Unless the OCR1 is totally mint (and maybe even then) $530 is more than it is worth IMO. The OCR2 is much more in line, especially with the ad ons. These from a private seller or used at a bike shop? Same size?
If from private seller than offer $100 less on the OCR 1 and $50 less on the OCR2 for sure and think about the same at the LBS unless they are giving some amount of service.