You might pride yourself on re-purposing unwanted materials or completing projects at minimal cost. There are many root cellar designs on this list for you.
There are also a few of the high tech variety here as well if you have the time and a little cash to work with.
Plans for a traditional underground, full height cellar.
Can you locate an abandoned school bus? I bet you could… (this is #8 from the slideshow forthcoming).
Follow the link to the 17 root cellar projects compiled by Homestead and Survival.
17 DIY Root Cellars For The Homestead