Here is a product that converts your regular desk into a stand-up desk. The DC200 Stand-Up Desk Converter is height-adjustable and lets you work standing up without having to buy a whole new desk. You can raise or lower the desk surface with its gas strut design. You get enough space for your keyboard, mouse, phone, and accessories. The work surface can be rotated.
The DC200 has a sleek wood construction and tapered rear portion to fit corner cubicles. Its heavy steel base prevents tipping. This sets you back under $200.