Well, they're not rubbish. Like any instrument, though, try one out, get a feel for it, see whether you really do like it or not. Does it sound how you like a kit to sound? Do you actually feel comfortable with it? Try one or two others, too, and take a few weeks over the whole process if you can. At the end of the day, if you still really like it, and it's at a good enough price for you, then I'd say go for it.
On the other hand, don't buy one just because it's what your favourite drummer plays. You may play like him or her, but you will never actually be him/her, no matter how much you emulate their style/kit/technique etc.
Might be worth popping along to http:/www.mikedolbear.com . There are lots of really nice, helpful people on there who know a lot more than I do and don't mind sharing their expertise.