Try to recycle as much as you can (you would be surprised at what you can make use of - I used an old dresser and mounted my cutting board on it - the drawer space was invaluable) and at the least have your machines and maybe your iron on a dedicated power strip. This way you can shut those off all at once if you don't need them while you are cutting/pinning/basting, etc.
My daughter also got me for my birthday a Skull Candy iPod docking station. I don't have a cable hookup or internet connection in my sewing room but I can play the music on my iPod and the docking station is really little but with great sound. I have a 10 x 12 room and I posted pictures in the virtual room on this forum - take a look. I did most of it for free and you mentioned you needed to keep the cost down.....