I got a simple A5 trust one, it was about £25-30, I was expecting it to be pretty naff but thought I would give it a go for a while before saving up for a wacom, but ive got to say its pretty good for me anyway, I didnt/dont think that I would use all the extras on the higher priced tablets, but if I now tried one I might find theextra pressure levels etc a great addition. Got to say though the mouse is horrible though, and when I mean horrible I really mean it!
Ive had it for about a year and its been a great little tablet, goes with me to and form work with my laptop and its never had a problem.
I mainly use it for Zbrush and PS work, I tried to get used to it for everything but, i well cant!
I would say that if your going to use a sculpting package then a tablet is a must, I kept sticking to using a mouse with Zbrush, looking back now I must have had a screw loose!
"No pressure, no diamonds" Thomas Carlyle