Hi all. I just went to the Apple store, and my friend (actually she is older than I am, like 15 years in difference. Just got friendly, so I call her 'friend') suggested me 100$ for 4GB upgrade. She told me that it's not possible to upgrade the RAM after the payment, but she is able to do it for me. I'm always paranoid wether the Apple employees will give me the 'older' RAMs or 'used' ones. Should I be? or just trust the employee who will swap it for me. If I have a choice, I would like to install the new RAM for myself. Is that possible in the Apple store?