I bought 6 at a time in the Picardie ones from Jetblack. They Duralex ones are great - though I was at a cafe the other day, and they dropped an empty one on tiles, and it broke HARD - thankfully no shards, but it travelled a good 3m or so. I have dropped mine a few times, and not even a chip out of them. They are about six months old, go through the dishwasher, and get treated pretty badly, and they still look new. I mostly drink picollo's, and the 90mL are perfect. I only use the set of 6 ACF 70mL tulips when all the other ones are used. Also, for the price of them, consider getting the set of six by the time you factor in freight.