Hmm..bluenile is still higher priced in my opinion.
OP, you may want to surf some of the threads in here. Use google or something. They have some good information here and there.
One tPFer suggested to go to auction houses to buy that perfect stone. Others followed this advice and bought a Tiffany ring at an auction house for fraction of the price. While I agree, sometimes..like foreclosure homes.. people just don't know where to find these auction houses. Also it's a luck of the draw, sometimes that perfect diamond is available, sometimes it's not. Some tPFers will suggest to do a certain thing, but if you look deep in their history...you'll know why they suggested it - if that makes sense.
Some jewelers will not negotiate prices...but if you do a bit of research you will find it's because they already offered this at the best price and they just don't feel like negotiating. These jewelers are rare.
Be ready to walk away and have a good poker face...because if the seller knows you really like that stone, this seller will not negotiate any lower. Same is true with car dealers.
I agree with Ame. Do a bit of research first. Good luck.