It's hard to find a small TV for cheap anymore, unless it's LCD, and then it's not cheap.
I got a 20" non-HDTV for under $100 at Best Buy. It has a remote and the picture looks nice. It's small enough to stash away somewhere and is light enough for one man to carry.
You can find LCD 15 inch displays pretty easily, ranging from $400-1000. They're very small, like an LCD computer monitor, and easily stashable.
Also, you may consider getting a media center PC and computer monitor. You can get a 19" LCD that is not much larger than a 15" in terms of stashable storage space, but makes a HUGE difference in viewing enjoyment, for less than $300. I have a widescreen 19" that cost only $300. If you already have a spare PC laying around you can add on a TV tuner card and SageTV software for about $100 combined (SageTV may even have a combo deal).
If you're not going to use it much, that may be a better option, and then you can do other things with it other than watch TV.
If you want, you could probably use your laptop and a USB tuner card, which is what I have. It's a bit more expensive than the internal one, though, maybe $150 just for it. But if you have a fairly decent PC (or mac that can run FrontRow) it's a good option.