I'm buying a base model 13" MacBook Air within the next week or so but I'm having a hard time deciding between 4GB RAM and 8GB. The obvious choice is 8 to future-proof it, but right now, I can't seem to find a good/fair price for it. On the Apple site, the RAM upgrade is $90 [EDU price]. However, B&H Photo charges no tax and their AppleCare warranties are 50% off. They also have a $50 cheaper base price model. The kicker is BHPhoto sells the 8GB upgraded version at $200 more than their 4GB model. I will go with B&H regardless, but it just feels like an unfair deal for the 8GB upgrade. Thoughts? Is my best bet eBay?