The difference between diamonds and designer bags is this, diamonds are diamonds, a well cut gia certified stone say 2ct vvs2 g color is the same if you purchase it from a local jeweler or Cartier, you can't say the same about handbags.... I see no reason to pay extra for a diamond because of the name of the jeweler, however if there is a particular style setting or jewelry design that you can't live without that is proprietary to a designer I don't believe in copying that. Personally I would prefer to go more custom anyway though. My setting is Scott Kay and I love it, fortunately I don't see THAT many like it, but if I were getting a ring now I might be considering something more unique, but maybe not because after 9 years I do still totally love my ring. Good luck!