Rob, here's a link to the Indoor Gardening Supplies Co. website. I bought my light cart from them about 15 years ago. Click on Value Line and Compact Carts on their products listing - there may be something there that fits your budget.

Here is a link that might be useful: IGS

My husband added a shop light under a shelf on my stand and it works fine-its on chains so its adjustable-doesn't look beautiful but sure works.You just need to find a shelf as wide as shop lights at an unfinished furniture store or thrift store.Posy Pet

A lady on the Citrus forum has had excellent results using a halogen shop light. This is the kind on a stand and has two light fixtures attached. It reates a lot of heat and a lot of light but she swears by it.

When you get ready to build your own check the 'Growing under lights' forum. Here's a nice plant stand and cheap too.!

Here is a link that might be useful: Easy to build light stand

You can put something much more functional together yourself. I am providing a link to a stand that holds a LOT of trays. I am using a similar plan but stacking cement blocks on the ends (the square ones used to make cheap bookshelves). I like my plan also because it's easy to dismantle during the off-season.
http://www.taunton.com/finegardening/pages/g00047_pe.asp