I'm never visited Greece, but I think that all tourist traps have a lot of souvenir shops.
Do people love making money off other people? Always check the price before you buy.
More than you will care to visit.
Beware though, that some of them are exclusive outlets of label products and may be somewhat expensive.
Anyway, you will find anything you like even if you visit the island in the off season period, as it is now.