Maui Jims are a brand of designer sunglasses that, as of 2009, can cost anywhere from $100 up to $300. These sunglasses are sold exclusively at Maui Jim stores or stores that have been authorized to resell them. Sometimes, however, a tempting offer may come up on eBay, but you should be sure that you are getting the real thing.

Inspect the sunglasses carefully. Anything that looks cheaply made probably is. Loose or missing parts are a dead giveaway, especially if the glasses are missing a reference number on the arm.

Avoid online sellers that use stock photographs from the Maui Jim website. Always ask for pictures of the product they intend to sell you.

Be wary of those who ship from places like Eastern Europe, Africa or Asia, as these places are known for selling faked goods. If your gut tells you the sunglasses are a fake, they probably are.

Look at the price. While you can surely get a good deal on sunglasses via the Internet, be wary of anyone offering the glasses below $50 to $75. If the glasses retail for $100 to $300 new, there is no reason why anyone would resell them for under $50.

Look for the "Maui Jim Authorized Reseller" sign if you are purchasing a pair of sunglasses in person. This guarantees you are purchasing authentic glasses. You can also go to the Maui Jim website and perform a store locator search to find an authorized reseller near you.

Call Maui Jim at 1-888-666-5905, when in doubt. Give them the product's reference number. They should be able to verify if any sunglasses by that number have ever been manufactured. If conducting business online, ask the seller the model or reference number of the product in question.