I order 2 cans at a time from sewforless. Theirs are the larger cans made in Europe (red instead of yellow; same stuff), so I think they are a better value than might appear at first glance if you are comparing to the large yellow cans. The large red cans are 17 oz, whereas the large yellow cans are 11.5 oz. Here's a link to the cans I order (which I think is the same type as you are looking at by the case):
http://www.sewforless.com/item/505_T...OUND_ONLY/7391
I personally would not order an entire case just because I'm sure there is a shelf life to these things. How long do you think a case would last you? I would be afraid that a can older than a year or so might not work so well anymore. All of these sprays are made with chemicals, and chemical reactions over time can make a spray perform differently, I think.