Sorry, I have to agree with everyone else, when it comes to booties. gloves and wetsuits, you're taking your chances by ordering online. Sizes also vary between brands and sometimes between models of the same brand. If you're really, really cheap, try the specific model at the Local Diveshop (and bring your fins as Mike_S suggests, to be sure they fit your booties). And if the savings are really significant to justify doing so, then purchase it online. I usually wait till the LDS has a sale to purchase these - gotta support my instructor/diveshop.
My favorite online shops are scubatoys, leisure-pro and divers direct, but I believe they all would have charged you for the shipping (both ways) in this situation.
Dive safely.