What if you didn't have to go to the supermarket all the time?

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You're all set for the weekly trip to the supermarket, but you're just not feeling up to making the drive and walking the aisles in search of bargains -- and the less said about all that loading and unloading, the better. What if you could sit in front of your computer and take care of the weekly shopping with a few mouse clicks? It sounds great, but all of that convenience has to come at a price, right?

Well ... not necessarily. In fact, if you shop carefully, you can actually save money buying groceries online.

Before we explain how, let's break down the two basic types of online grocery shopping. You can order online from a site such as Amazon.com or Alice.com and have groceries shipped to your house, usually within a few days. Or you can order online with a local supermarket, either for delivery to your home -- sometimes on the same day, if you order early enough -- or for curbside pickup.

If you're having the groceries delivered, you're saving the money you'd spend on gas to get to the store. If you pay a delivery fee, you can easily figure whether that costs more than your gas would have. Alice.com and some other online sites offer free shipping. In 2011, Wal-Mart promised to deliver your purchases for free if you spend at least $45. Others have graduated fees depending upon the size of the order. Many waive the expense the first time you shop.

There are also usually fees -- at least after your first purchase -- for ordering for curbside pickup. If you're a smart shopper, your savings probably more than make up for the fee.

On the next page, we'll tell you how you can save money shopping online.