I guess that would depend on your definition of cheap. Obviously, many people enjoy the ECB smokers, and although I do not own one, I hear that they do a very good job once a few minor modifications are made. If you are interested in this type of smoker, do a search for ECB and you'll find tons of happy users and tips. I believe these types can be had for $40-$90 depending on size, heat source, etc.
Once you break the $100 point, the options open up a bit, but beware that there are some tempting "looking" units out there that will make you smoking experience much less enjoyable than it could be for a few dollars more. For example... there are several offset models that can be purchased in the $125 range, and while these models will smoke food, they seem to be a little more finiky as far as maintaining temps and eliminating air leaks. Now... I'm not trying to crack on anyone here, we use what we've got. I don't have the "best" smoker by any means, but with help from some of the good folks here, and borrowing some of their ideas, it works much better than it did out of the box. But, it took a lot of trial and error, and practice to turn out what I consider to be acceptable results. Heck, ok... sometimes they are darn good.
To continue... I have the Brinkmann SnP Pitmaster Deluxe. It does not have a top rack or firebox door (a.k.a. air leak hatch) like the standard SnP, but what it does have is heavier gauge steel all over, and I mean perhaps twice as thick. It feels fairly solid compared to many I have lifted the lid on, and I think this helps to retain heat a little better, and the weight of the heavier doors probably helps to seal them better as well. Mine was a gift from my Mom, but I think she picked it up for $170 at ACE Hardware... well worth the extra $50 in my opinion.
Of course there are others that exceed the $200 range. Many of the vertical smokers look real nice, and I'd like to try one, but for some reason I feel like I'm doing it right with an offset stick burner. Probably because that is what I learned (still learning) on.
I'm sure you'll get several opinions, that is what's nice about this place... ask a question and get swampped with informative replies. I will add one of the best pieces of advice I've got here... buy a digital temp probe (or two, or three) in order to monitor your meat. I have had much better results since I've started using these things. Takes the guesswork out and you don't have to open the lid (i.e. let the heat out) to check your progress. A decent one can be had for $10 - $20 at Wal-Mart, Lowes, Home Depot, etc.
I hope I haven't confused the matter for you. Basically, no matter what you get, there is probably a way to make it work the way you want. It seems that almost all the lower end models require some type of modifications to make them really enjoyable to use. If you don't spend much, I guess you won't be out much... and, if you get an ECB, you can use it in conjunction with whatever you might pick up later. Heck, I've thought about getting an ECB just for the heck of it. Some days I don't feel like firing up the SnP, and wish I had an ECB for a few ABTs or a fatty. Decisions.. decisions... a lot to consider.
Edit: WOW... look at Fred's post down there... I didn't know GOSMs were that cheap. A lot of people seem to like those too.