There is so much bad advice on this thread I don't know where to begin or really have space to address everything. But having just been a buyer I would offer the following:
(1) If you don't do anything else, go to
pricescope for sound advice on buying a diamond (yes I know it's referenced above - one of the few helpful tips).
(2) A diamond is a big big investment. The most important thing is to find a trustworthy jeweler who will sell you a certified stone at a fair price. good heavens I love miles as much as anyone but they are really secondary at best. 20 years from now those miles will be spent, but that diamond is forever and you will be pissed if you get stuck with a crappy one because you wanted a few thousand miles.
(3) As is true with most things, you get what you pay for. If you go to costco, you will get a costco quality diamond. Really. It will be a crappy cut and worth every penny you paid - but no more. If you go to Tiffany you will get an excellent diamond but pay a premium for the blue box. Your best bet is a reputable local jeweler. If you live in a small town and don't have one, then perhaps you should consider bluenile or ashford, but they would not be my first choice.
(4) While online merchants such as bluenile are reputable, online shopping is is NO substitute for shopping in person. You really can't see the subtle differences in cuts or color on a screen, and the inclusions are highly magnified and therefore a bit overstated. When you shop in person, you may find (as I did) that inclusions are less noticeable but color is very important. Or vice versa.
(5) Do not buy overseas. You will have no recourse if you get shafted (which is highly likely) and the prices are not any lower as diamonds are traded worldwide. If it looks too good to be true, you are probably getting a diamond that is not what it appear, usually not as good a cut, but possibly deceived on color, clarity or one that has been modified (laser filled).
(6) If you remember nothing else, the most important item is the CUT. That determines how much your diamond will sparkle. Everything else is secondary (provided of course that you don't go with too low of a color or clarity). The advice to go for the biggest carat you can afford is laughable. How will your wife feel when her big diamond looks yellow and dull next to her friends? Yes, it may look great in the store, but it won't look great by comparison if it is poor quality. Like most other things in life, it pays to buy the best quality you can afford.
Good luck!
And to those who are curious, I found that blueniles prices and quality were excelllent, but they could not beat the price or service of my local dealer. And yes, I charged it on my Citi AA card. Why not get the miles?
