I purchased my diamond earrings at Neiman Marcus (G-VS1 ideal cut hearts and arrows 2.06 TCW). I used to have a larger set of studs -- 3.30 TCW (I-SI2 ungraded). They unfortunately disappeared when workmen were at my house. Luckily, they were insured. I went back and forth on sizes, but ultimately concluded to go smaller and better quality.
My stones were certified by EGL USA. My good friend and SA searched Neiman's inventory and these were on sale just below Neiman's cost. She showed me the internal paperwork. There was a battle among SAs in differing Neimans locations for the earrings, but my SA got them in for me to look at and it was a done deal. I also got a very nice Neiman's gift card with the purchase.
I absolutely love the earrings, even though they weren't certified by GIA or AGS. They were a great price and are of truly lovely quality. They sparkle like mad.
I know that Saks carries Graff. But there is an enormous premium for the Graff name. I looked at similar size studs (2+ CTW) that were F-VVS and the cost was $42K for the pair. They had a pair of D-IF for something like $70-$80K.