Everyone wants the most for their money these days, so we are often asked about the best air purifiers. It can only be considered cheap if it does what you want it, and you are shopping for a good price. However, if you purchase an air purifier for any price, and it does not solve the problem or solve it in a reasonable amount of time, then it is not cheap, in fact, but a costly mistake. Here are 5 ways to prevent a "cheap"> Air purifier an expensive mistake.