fresh vegetables

I have been thinking a lot about food preservation because I just moved out on my own about three months ago (i’m nineteen) and I am finding out that an average person spends a hell of a lot of money due to the fact that various foods have to be stored in a certain way and go bad quickly even when stored properly, causing the person to buy smaller quantities of food at high prices. What is the root of food going bad? Is it air? If so I want to get a huge chamber like a fridge or something with a decompression system to suck all of the air out everytime the door is closed.
brocolli and spinach and fresh fruit and everything else should last a very long time in this kind of environment. What would be the best way to go about obtaining a device or something similar with the lowest cost in mind? And maybe even portable smaller devices for travel. Any information on this topic or anything related to the affects of air on food would be greatly appreciated.

This thread is a double post (I’m sure by accident) of fresh vegetables.

I’m asking the mods to close this one.

Peace.