the setting from a chain. No jeweler could come close to the price and quality of what I got from blue nile. Then the advantage of a chain for the setting is that they will clean it and repair it for free every six months.
Also, when assessing quality, many people recommend choosing clarity over color. I don't think I agree at this point. My wife's stone had a high clarity rating but lower color rating. I suppose it's nice knowing that you could look at the stone through the lens and only see one tiny imperfection... but of course after you leave the store no one will ever look at it under a lens again. And you can find many diamonds that are rated as low as SI1 (slightly impacted 1) where you still can't see the imperfections with the naked eye. However, you can definitely tell the difference between the sharp, cold reflection of a stone with a high color rating, versus the warmer, yellowish glow of a something with a lower color rating.
In other words, go with what looks best to the naked eye, because that's all you or anyone else is going to see it with.