Is it more important to upgrade storage or memory?

I am going to buy a MacBook Pro with Retina Display this summer, and I'm trying to decide how much storage and memory to get.

I saw a question that someone else asked; they had a laptop with 4 GB of memory and wanted to know if they should upgrade to 8 GB. The answer they got was that 8 GB was a good amount of memory, so I'm wondering if it would be worth it for me to get 16 GB of memory, or if 8 GB would be enough.

Also, in the same answer to the question I mentioned above, they said that 256 GB would be more than enough storage, so I don't know if I should stick with 128 GB or go up to 256 GB.

I'm on a limited budget, so I also want to know which of these 2 things would be more important to upgrade.

Here's the link to the question I have been referencing: http://store.apple.com/us/question/answers/mac/should-i-upgrade-macbook-airs-pro cessor-ram-or-flash-storage/QX9ATJAJHKYF…

Thanks so much!