You usually have to customize the order on Apple's website to do this, which means your laptop could take a few weeks to arrive. There's also other circumstanc

You usually have to customize the order on Apple's website to do this, which means your laptop could take a few weeks to arrive. There's also other circumstances where this isn't an option. When I worked at a public university (UC system) that had an agreement with Apple, we could only purchase hardware that was in the University bookstore. The University bookstore only stocked base models. Even the top-of-the-line 15" Macbook Pros didn't have a 16GB option once the RAM started being soldered down.