The thing about credit is this: The instant gratification can be addictive.
OK, there are actually a lot of things about credit. It can make you lose sight of the value of money; it can encourage you to buy things you simply wouldn't if you had to pay cash; it can blur the line between "want" and "need."
In other words, it encourages impulse buying in a big way.
Layaway, on the other hand, requires planning. When you buy something on a layaway plan, you'll be paying for it over an extended period of time, typically anywhere from four to 12 weeks. This delayed gratification dramatically decreases the "thrill" of the buy and makes you think about each purchase you make. In the end, there's a greater likelihood you'll make a more rational decision with your money.
You might even end up spending less of it ...