Melissa Barnes spends only about $30 a week on groceries. How she does it might surprise you.

"Most couponers will cut the coupons the day the paper comes out, and they'll go to the grocery store, or the drug store, and use the coupons that week," Barnes says. "But this system is telling you that's all wrong."

This system is 'The Grocery Game,' a website that gives shoppers the scoop on savings. Barnes has been playing for two years, and it's paying off.

"I'm saving at least 50, 60, 70 percent off, depending on the week," says Barnes.

Savings, she says, that add up to thousands of dollars a year.

Here's how it works: Every week, Grocery Game players get a list for each store they subscribe to. It's color coded: Buy black items only if you need them, they're not at the lowest price. Stockpile blue items, their prices won't get any lower. And green items are free.

"Checking a few boxes, clipping a few coupons, and going to the store--it's that easy," Barnes says.

The idea is to 'play' your coupon when the store already has the product at its rock bottom price, for maximum savings, and buying enough of it to last you 12 weeks, until the item goes on sale again.

Matching coupons with store sales will certainly save you cash. But it might not be the best way for every shopper to save.

"If you have the time, and the Internet, which some people don't have the resources for, it would probably pay off," says Joyce McGarry, a food and nutrition educator from the Michigan State University Extension.

McGarry points out other downsides, too. Not everyone has a place to store food in bulk, and the 'Game' in Lansing applies only to major chains.

"If you have some of the local stores, like we do in Lansing, it doesn't cover those stores, which may have just as good or better details," McGarry explains.

Plus, the 'Game' doesn't offer choices for produce, which shoppers can often find cheap, or generics.

"They're telling you to buy name brand products, when you can buy the store brands for a cheaper price," says McGarry.

And of course, you do have to pay to play. A four-week trial costs $1. To keep playing after that, it's $10 every two months, for one store. If you want to get the list for multiple stores, you have to pay more.

"To me, that's totally worth it, because I'm saving hundreds every month," says Barnes.

But if the extra money to play the grocery game isn't in your budget, McGarry has some advice.

"Just be an educated consumer," she says. "When you go into the stores, you take the flyer that they offer you, and you have the flyer in the paper, and you look at what's on sale and what's the best value."

Because everyone can win the saving game.