I will be going to Tahiti (and the island of Moorea, to be exact) in August for my honeymoon, and I was thinking about buying a pearl necklace while I’m there. Are they a good deal there? Are there any scams that I should watch out for? Would you recommend buying them in Tahiti or should I just buy them at home (U.S.)?

I heard that Tahiti Pearl farmers are holding (not selling tons) there pearl to increase their value and so pearl cost will rise. Make sure to compare prices, do not jump on the first store because many tour operators, taxis… will bring you there and will say it’s cheap, they have a pearl farm…. but reason is they get a commission from sales or a fee to bring tourist there. The only reason that you will buy there is for the "souvenir" so it was memorable having that pearl necklace in french polynesia for your honeymoon while you were there. I recommend you buying loosen pearls if you want to have a necklace made with gold, precious stones… bring back to U.S. and get a jeweler to do what ever you want with. If you want a pearl necklace like "knotted pearl" then you will have to put a lot of money. If you only want a small pearl pendent, then go for it.
Also to be honest, you can find cheaper tahitian pearls necklace in the U.S. market, ebay is a good source of tahitian pearl jewels but must know that photos are not as accurate as having it in hand so you can go to a jewelry store that sell tahitian pearls if you are not so confident about ebay. Because some jewelers buys by lots (1000+) they can have really cheap price, cheaper than any pearls sold in Tahiti. Some big markets are : U.S., Japan and Hong Kong.
Also Tahiti jewelers imports gold and cost of shipping + taxes are really high + margin so that’s why in U.S. they are cheaper.
My best recommendation will be: If your honeymoon is more important than money, then buy in Tahiti so you’ll always remember when you look at your pearl necklace. If money is your concern, you still can compare price first and buy in the U.S. but as dollar drop versus french polynesia currency chance are that some jewelers will not sell cheap because they won’t be able to buy "lots" of pearl sooner.
Tahiti is one of the more expensive places that you are ever going to visit. Purchasing pearls there is probably not a good idea. Morea is wonderful but at least take a day trip to Bora Bora. Its amazingly beautiful. Many people consider it to be the most beautiful place in the world. You can take the ferry over but I would recommend staying there as well if you have the choice.
Tahiti is primarily a Honeymoon resort with over 85% of all people visiting being on their honeymoon. So its not really a party place… more romantic than anything. But save your dollars for places that have better prices.
You should absolutely buy a pearl while in Tahiti! I bought my pearl (and pearls for my mom and MIL) at Tahia Collins. It’s a store on the west side of Moorea, actually a very short walk from Le Petit Village; if you’re staying at the InterContinental it’s within walking distance. The salespeople were very nice and informative, we never felt pressured. The great part about buying a pearl in Tahiti is that you don’t have to pay tax.
Enjoy your honeymoon! If you get a chance, go to Le Mayflower for dinner. It was our favorite meal on the island.
If intrinsic value is important, it makes sense to purchase your Tahitian pearls in Tahiti. If cost is a concern, you are better off doing your research in the US and purchasing in the US.
Tahitian pearls are extremely expensive in Tahiti (retail) because it is a tourist market. They are quite cheap wholesale, how the majority of pearls are sold. You will likely find a much better deal back in the states.