JB: I purchased my shelves at Wal-Mart @ 8 years ago; they were very reasonably priced back then but I see the prices have gone up quite a bit.You should check Wal-Mart, K-Mart and Target as well as Home Depot and Lowes ... and don't forget to ask a manager if any free standing shelving will be going on sale any time soon, they do have it on sale every so often. Also, check out a few yard sales for free standing shelves.
I have two this size that I paid less than $30 for @ 8 years ago:
$69.97 at Wal-Mart:
http://www.walmart.com/ip/Whit...
$62.99 at Target:
http://www.target.com/p/whitmo...
$79.97 at Home Depot:
http://www.homedepot.com/p/4-S...
They come in a smaller version too:
$34.97 at Wal-Mart
http://www.walmart.com/ip/Whit...
$34.99 at Target:
http://www.target.com/p/whitmo...