Stop right there. Put your money away. A lot of people are after your cash, and you, quite understand_ably, would like to hold on to as much of it as you can. It won't be easy: Last year, Americans frittered away more than $1.2 billion on dubious deals, an average of $2,057 for every consumer, according to the Federal Trade Commission. How do you tell the bargains from the boondoggles? Here's a look at seven offers that often don't pay off, plus smart ways to save your hard-earned money.