Whether you are looking to purchase a complete home gym, a treadmill, an elliptical machine, a rowing machine, or just a few sets of dumbbells, here's what you need to know to make sure you don't pay full price on your next purchase.

The fortunate fact is: there is generally a lot of gently used equipment available. Many times, a large machine is purchased only to collect dust until someone finally decides it's time to get the huge hunk of metal out of the home once and for all. Because this happens a lot, it's relatively easy to find a good deal on this kind of purchase (if you're willing to be patient and do a little digging).

The first step is to find out what type of equipment you want. Most of us don't have homes that afford enough space for more than one or two of these machines, so the research phase is going to be a crucial part of your purchase. You want to make sure that your machine doesn't collect dust, too. So go to your local gym a few times and see which machine you enjoy the most. Go to local sporting goods stores and try out a few of your favorite types of equipment so you get a good feel for what you want and need.

The next place you'll want to check is Craiglist. Here, you'll find classifieds for used items for sale in your area, which will make pickup easy. You might even find a piece that is free (or close to it) as long as you agree to go pick it up. Make sure, before you take any of these types of items, that the equipment still functions well and has all of the safety mechanisms still in place.

You can also check your local freecycle network, which is an organization in which participants offer their items for free, in an effort to keep them from being thrown away. If you don't yet belong to a freecycle group, do a search for local groups online.

Before you buy a piece of workout equipment, you will want to make sure to check out the deals on eBay or your favorite auction site. Of course, you'll want to pay special attention to shipping charges, but if you live in a large metropolitan area, you may be able to find something that you can pick up locally and won't need to be shipped at all.

Garage sales are another great way to find used workout equipment. Many times, large pieces of equipment, such as treadmills and ellipticals, will be advertised alongside the garage sale in the newspaper. If that's the case, arrive early because it's very likely to be a hot item. Make sure you try out the equipment, no matter how good a deal it appears to be. You don't want to be stuck with something that's unsafe or that just doesn't run right.

If you can't find the machine you want used, you can buy it new at a discount. Start by checking out the deals online. Shopping online makes it really easy to comparison shop a variety of different models. It's very possible that you'll find something at such a great deal that it will offset the shipping charges. Some online stores that also have brick-and-mortar stores in your area may offer a program in which you can comparison shop and make your purchase online and then go and pick up the item, or arrange for local delivery from the store.

The benefit of buying a piece of equipment brand new, of course, is that you'll have the warranty in place to protect your investment in case something goes wrong.