Hrm. The price on Intuos units has really jumped, there's not a lot you can get for less than $200-300. There's some older Intuos4 models available on Amazon (I bought my Cintiq through Amazon back in '09) for decent prices, but at your range the only thing I'm seeing are the 3x5 models.
Which are perfectly functional, I used a 3x5 for a couple years before I upgraded to a 6x9 (and then to the full Cintiq). Drew some 15 pages for MESS Studios on a 3x5. But if you've been working on a larger tablet it's going to be a little awkward.