DK Gems for sure. Great prices, great selection, and very friendly, non-pushy customer service. They keep records of everything you purchase and if you come back in future years and want to trade in your earlier item for a bigger/brighter/different/whatever item they give you your full original purchase price as a credit towards the new purchase...no matter how long you have had it.

Everything we have purchased there appraised at 2x to 3x what we paid when we have them analyzed here in the US when we get home.

Make sure you ask for the "TTOL discount"! The price on the tag is ->considerably<- higher than what you will wind up paying after applying that discount...