Ebay, you choose the price you start at and they help you through a safe selling process
Gucci has stores in Vancouver and Toronto in Canada. Holt Renfrew does carry the Gucci brand and have stores in both Calgary and Montreal. You may just have to phone around to optical stores to find out what brands they carry.
Desert Hills outlet in Cabazon just west of Palm Springs has some great outlets. There's Coach, Gucci, DKNY, a whole mess of them...