If I were to order a machine with additional memory, it seems this would lock me out of the option of doing a return within 14 days if I wasn't happy with it. Would I still have the option of sending it back in order to buy a more expensive machine? Specifically, I don't want to buy an iMac unless I'm really stuck and am hoping that a maxed out mini will be more than fast enough for light video editing, photoshop etc. If I play with one and determine it's not what I;d hoped for, I'm hoping to have the option of sending it back and paying the difference for an Imac, without incurring additional fees. Does anyone know if that kind of thing would be possible?