besides tiffany, there are DeBeers and Cartier which are about the same level as Tiffany. I personally prefer DeBeers and Cartier to Tiffnay. And I got DeBeers 

Also Tiffany offers 0% apr finance, but you can not negotiate price. The other 2, i believe you can cut from their listed price. For DeBeers,you have to pay full amount at purchase.