Company I was previously with has a Tiffany corporate account and we got 15% off a watch that we gave our HR director as a going away present but this discount unfortunately does not apply to any diamond jewelry.
Though recently when I bought from Tiffany, I got them to resize my old engagement ring for free which would've normally cost $175 and I also got 2 valuation reports on some diamond items that I have lost during my move, those valulation reports would've cost me $200 a piece so I thought that was a pretty good discount in the form of customer service.