Cheap fish + unexperienced fish keeper = cheap results. If you are getting fish based on how "cheap" they are, you will most likely get some kind of disease in your tank. I agree with the above poster who said you should look for good quality fish, instead of going for "cheap" ones. I also think you should research the fish you intend to get before you get it instead of just going with whatever is on sale. Some fish are incompatible, and better to know earlier than later. Good luck.
Sandy
Sandy