So I just bought a 32GB iPad. Anyways, when I hit place order, it said $638 with tax. So 2 minutes later, I get an email confirming my email, and then it says: estimated tax: $54. So I checked Chase, and they charged me $638 and then they have another charge for $17. Why is this? Was the tax just more than they thought so they charged me more? Or what? Thanks! BTW I bought it online, and it's being shipped to the Woodfield Il store.