i wouldnt go for a cheap one... the cheapest i know is the wacom graphire... its a little above $100, but its not that great, as its pretty high and has weird edges that makes resing you hand against it not so nice.... I have an intuos A6, its about twice as expensive, but it was DEFINITELY worth it... cause theres absolutely no way youre not going to like the tablet... i just hope you dont have an optical mouse, cause you might just as well throw that out . The intuos is a bit bigger (not the drawing area, but around it) so you can comfortably put your hand on it, it has a few extra menu buttons (quite helpful if youre into layers and so on a lot) and its way more sensitive than the graphire... and at $200 its not that expensive either...

and if youre one of the art-class draw-with-your-arm kind of guys, youre probably going to have to shell out a lot more than that... but if youre happy drawing from the wrist, A6 (the smallest) is a perfect size (at least for me it is).

Weird. It''s not the hand-wrist thing for size, it''s the scale between my monitor and tablet. If I move my pen half an inch on the tablet, I feel like it should move about that distance on the screen. I''m not looking at my hand either, it''s just that my brain gets confused.