Hi Lisa,
I remember a thread about a year ago concerning flooring. One girl had suggessted livestock mats.
We have a hog farm and my husband gets livestock mats for the pigs.
We built my exercise room in our garage. The most expensive part was carpeting the whole garage.

But I put 2 livestock mats down over the carpet and then put carpeting on top. The mats are so heavy that they won't go anywhere. The measurements are like 5'by 11'. These were the pieces my husband got for me anyway.
I figured if they were good enough for horses and our pigs, they would work for me. I think the cost was around $40.
Some of the girls used mats that you put together like a puzzle. I tried to find them but couldn't.
There are alot of possibilities and I'm sure you will get many good suggesstions.
I have a cabinet on wheels with two shelves that holds my TV, VCR and part of my tape collection.
Have you seen Francine's pix? She has a mirror I'd love to have. ;-)
Have fun putting it altogether. I'm still work in process but my motto is: This is my space and where I'm spending alot of my quality time. So I went wild with color. Ever see a fushia colored furnace? LOL
Wanda