Almost nobody will tell you to carry a .22 if it is at all possible for you to carry a larger caliber.
I don't know where you are, but Bersa .380 pistols (kind of like the Walther PPK), go for $200 or so at Academy Sporting Goods. Here's a rewiew of them:
http://www.gunblast.com/Bersa_Thunder380.htm
The Kel-Tec, as mentioned above, comes in the widely-available, sufficiently powerful, and very affordable 9mm round, and can be had in the low $200s new.
The Hi-Points get a lot of debate: some say they're a good buy for the $, others say they're junk. 99% of people would agree that they're too bulky for comfortable concealed carry.
Avoid the following brands like the plague: Bryco, Jennings, Raven, Phoenix, Jimenez, RG, etc. Total junk, not worth $50.
Look at it this way: even a halfway decent gun will last for decades. Unless you're living out of your car, you really want to spend the $200 or so for something decent.
You might even be able to find a good Taurus or Rossi snubby revolver for $150 or so. Solid steel and durable, if not fancy. Read the sticky at the top of the Revolver forum to learn how to check out used revolvers.
If you're going to trust your life to it, a) don't buy .22, that round is for shooting paper or squirrels b) don't buy junk. $200 isn't that much money compared to $119+tax. Knock back a few fewer beers for a month, or go a month without cable, and you'll be very glad that you bought something decent.
Good luck. Stay smart, stay safe,
-MV