Just called the Apple store to make sure they didn't have any 13inch MBA with 8GB RAM (128 or 256 SSD) and they said while they don't have any there, that I could purchase the 13 inch with 4GB RAM and they would upgrade it there on-site. I asked if he was sure and he said yes. Asked if there was a fee, and he said only the fee for the RAM hardware. Thought the upgrade to 8GB RAM was only possible through Apple store online. What do you guys think?