Newbie here - this may already be an answered question but I couldn't find a thread on it. I must be missing something when looking at MBP 15 inch configurations and prices so I would appreciate any help. Simply put, there are two ways to construct a 15" MBP with the 2.9 GHz upgrade and 512 GB storage: 1. Start with 2.7/512 configuration and add upgrade to 2.9 GHz. So, $2799+ $200 = $2999 2. Start with 2.6/256 configuration and add upgrade to 2.9 GHz and upgrade to 512 GB. So $2399 + $300 + $200 = $2899 Why do the prices differ? Both are allowed for order in the Apple Store at these different prices. Is option 2 exactly the same machine as option 1 or is it put together from a different base and maybe less efficiently constructed? Am I missing something else? Thx.