D IF 3.01 ct at Costco for only $283k. I threw the proportions into HCA and got only a 2.0... but they do have a good return policy!
https://www.costco.com/Round-Brilliant-3.01-ct-Internally-Flawless--D-Color-Diamond-Platinum-Solitaire-Ring-%24282%2c999.99.product.100041297.html


https://www.costco.com/Round-Brilliant-3.01-ct-Internally-Flawless--D-Color-Diamond-Platinum-Solitaire-Ring-%24282%2c999.99.product.100041297.html