Check the temperature in hell. One of the longest-standing truisms in buying a Mac is that you don’t get competitive prices when buying memory upgrades direct from Apple. Historically, Apple has charged exorbitant prices for RAM upgrades in build-your-own configurations — upwards of two or three times the market price, sometimes even higher.
So the standard advice has always been to buy your Mac with the standard memory configuration, and then purchase memory from a dealer such as Crucial or OWC or Newegg and then install it yourself. My assumption has always been that Apple could get away with such pricing because many Mac users just aren’t comfortable installing RAM chips by hand (even with machines where the memory slots are easily accessible) and are therefore willing to pay a premium price to have it installed by Apple.
But it ends up that Apple’s RAM pricing for the new MacBooks and MacBook Pros is extremely competitive. There’s only one upgrade configuration — going from the standard 2 GB to 4 — and for both the MacBook and MacBook Pro, Apple is charging $150. This same upgrade costs $142 from Crucial, $135 from OWC, and $160 (!) from Newegg. Factor in shipping and it’s pretty much even.1
This may not remain a good deal forever. My hunch is that Apple will continue charging $150 for this upgrade at least until the next MacBook revisions arrive; the prices at third-party memory stores fluctuate as commodity pricing changes. But for now, your best bet seems to be to buy MacBook memory from Apple when you buy your machine.
Apple’s prices for memory upgrades for other machines remains high; RAM from Crucial, OWC, and Newegg charge half the price or even better for machines like the Mac Mini, iMac, and Mac Pro. The most egregious example is the Mac Pro. Upgrading to the maximum memory configuration of 32 GB from Apple will cost you $9,100; the same upgrade from OWC costs just $1,680 — a difference so large that you could buy a second Mac Pro also maxed out to 32 GB with the savings.
One can argue that Apple is still charging a premium, since they’re charging $150 for the difference between 2 GB and 4 GB, whereas the third-party dealers are selling you 4 GB of RAM straight up. The effective difference is that when you upgrade the memory yourself, you get to keep two useless 1 GB RAM chips from Apple, but the out-of-pocket cost is about the same. ↩