In my local Apple Store, when you ask the staff they'll tell you they have "limited amount of supply" for all 3 models of the rMBP (2.3/8/256, 2.6/8/512, maxed out) but when you ask them to actually search for available stock because you want one, they will tell you the 2.6 and maxed out configs are sold out, and only the base model is available. I bought the base model eventually because I still can't justify a $600 price difference just for 256GB more of storage. The upgraded CPU is actually priced the same in the market.