I think I know what tablet you are talking about. My brother got one and didn't like it. It was cheap and didn't run well. $100 isn't a lot for a tablet, and it is true when they say, "you get what you pay for."
You need to be asking about the hardware manufacturer and definitely looking at the specs. Remember Android is just the OS. Just judging by the price, it probably can't even run Android 2.0 which is soon to be outdated. You should also read reviews online. As a general rule of thumb, you get what you pay for.