Attached Link: http://kb.adobe.com/selfservice/viewContent.do?externalId=tn_15281

Just have the seller transfer the license to you, (see link).

Also note that the difference between Illy 9 and Illy CS2 is huge, while the difference between CS2 and CS3 is marginal.
Point being, CS2 will most likely do everything (and then some) to meet your needs negating the need to upgrade to CS3.

 

Chuck