That's the neat thing about this hobby. You can decide to start small, learn what you like and dislike, how often you smoke, etc. If you want to start out for around 60 bucks then Dan's suggestion is great. You can use charcoal, briquettes, lump, small chunks of wood and you have a water pan between the fire and the wood to help a bit with temp regulation and to add some humidity to your smoking chamber.
If you know you want to be serious, but not spend a bunch of time tending fires you can look at any of the vertical propane or electric smokers. On the electric smokers you can kind of set it and forget it because the thermostat controls the chamber temp, you add smoke chips to a pan to get the "smoke flavor". You can also decide to be a "wood" guy and purchase an offset smoker, where the firebox is to the side of the cooking chamber instead of directly beneath it. You will spend between 300 and 400 dollars for a decent one made of heavier metal. Look at some of the larger offsets/reverse flows and you will see that the sky is the limit when it comes to size and expense.
I suggest you read some of the reviews available on this site and take a look at what you want to do in the hobby. No shame starting small and working up to a bigger piece of equipment.