If you are looking for some rare winx stuff or foreign stuff this website is awesome. I have ordered from them before and they are reliable and honest. I believe they ship from Italy so the shipping can be pricey but overall they aren't too expensive or outrages on the prices. Shipping can take a while too if you live in the states, but to me it would be worth it. I am considering ordering some winx power show stickers whenever I get spare money since I always wanted to finish that collection and still haven't (I started that like 6 years ago).
http://www.muscara.com/webstore/search/keywords,winx+club/page,1