Pricegrabber

• Search Pricegrabber for the Garmin GPS you're interested in purchasing. Pricegrabber itself does not actually sell anything, instead the site gathers prices from a variety of retailers online and compiles them together on one page. At Pricegrabber you can read reviews for the particular unit you're interested in, compare prices at a variety of online locations, and read reviews of the different retailers to make sure you're purchasing your GPS from a reliable source.
  
  

eBay

• Check eBay and see if someone is selling the Garmin unit you're interested in buying. A lot of small businesses sell Garmin GPS units on eBay, often at significant discounts. You also may be able to find a regular individual on the site who is just looking to get rid of their Garmin GPS for considerably less than retail. Before bidding on any item on eBay make sure to read through a the seller's ratings to check out their track record.
  
  

Electronics Store

• Check your local paper for deals of Garmin GPS units. If you find a particularly good deal in the newspaper or online, many electronics stores such as Best Buy will match their competitors prices, in some case offering you an additional discount as well.
  
  

Garmin Website

• Garmin often offers special deals and incentives for people who purchase their GPS directly from Garmin. Check the price of the unit you're interested in on Garmin's site to see if you can get the device cheaper or with more accessories than you can at other retailers.
  
  

GPS Specialty Stores

• There are several online retailers who specialize in selling only GPS units. Since they sell such a high volume of GPS units they can often offer them at lower prices than their competitors. Try doing a Google search for "GPS Store" to pull up some popular options. One store simply called "The GPS Store" offers sizeable discounts for Garmin GPS units over their MSRP.