Go for the Hermes. You can get a 1 carat diamond ring at a wholesaler much less than the price of Tiffany.
I agree with both on this.... If you are already married and have a ring I'm not a huge fan of replacing rings therefore I would opt for the Hermes, on the other hand if you're not married why buy the diamond yourself so I guess that equals still buy the Hermes, LOL. That said, you could get a beautiful non-tiffany 1ct diamond for much less than tiffany prices so maybe you could eventually get both! that probably didn't help you at all though.