oh no, you just opened my personal pandoras box. i could go on and on about this topic.
First hing you need to do is figure out what kind of smoker you wanna get. the basic choices are a traditional wood fired smokers that uses hardwood and/or charcoal as a heat source; good ol fahioned fire. You can alos choose gas fired smoker, shich used propane as the fire source and they usually have some type of cast iron vessel that you put soaked wood chips into that create the smoke. And then there's the electric fired smoker, which used some sort of electric heating element to heat up little wood pellets or bisquits and that's where the smoke comes from.
Once you figure out which way you wanna get your smoke, then you decide how much you wann spend. As with anythnig, this can vary. anywhere's from $100 to many thousands.
In figuring out shich smoker you wanna get, you'll need to decide how much attention you wanna have to pay to it while cooking. At let me preface this by saying you should avoid the electric smoker...we're all gonna laugh at you if you go that route.
With the traditaionl wood fired smoker, you'll need wood and charcoal. Charcoal is easy, but wood can be difficult. Woods like mequite, hickory, apple, cherry can get expensive. Chunk wood of these varieties are pretty accessible, but try finding those woods in real fireplace sized pieces. THat's tough. Also, the costs can start racking up with buying big bags of chunks.
Gas fired uses chips for the most part, which is a little less expensive.
OK, i'll stop now. Answer those couple of questions first, and then we can go from there.