Judging by the tyre size I would say this is probably an 8.5" width wheel? What you really need to do is get in touch with an AC Schnitzer Distributor to find out the offset which will determine what cars it will fit.
A good set (4) of original ACS Type III Racing 19's will go for in excess of £1k, however for only one this may be a problem. First as mentioned you need to determine the offset and then you need a buyer, generally somebody with the same wheels obviously that may be on the lookout due to damage etc.
Had these wheels on my e39 M5 and they are without doubt one of the sexiest wheels available IMO.
Good luck with the sale.
C.