Wrong, Master Shake.
It's not 10$ for double space for an entire year. It's 10$ for double space (initially, if you never upgrade it again) as long as you play and are a gold member. If, in a year, the game is still around and you're still playing, you can have your 40gb gold server not for 30$, but 20$. If you decide to wait a month and then become gold again, it's still just 20$ for that 40gb server.
That being said, I'd generally rather have the food. Thanks.