I just picked up my 13" yesterday (2.6 / 16 / 512) for $1850 and I was immediately furious that I saw this post.
Then I looked at it.. $1529 for the 2.6 / 8 / 512. Okay so no 16GB of RAM, that was a $180 upgrade. 1529+180 = 1709.
So really me returning and getting a refurb would net me ~$300 savings, but relatively only ~$100 with respect to RAM, and then even less considering time involved. (probably negative at that point)
Sorry, had to write this out to get my logic in order.
/WHEW