I got my ring from Brian Gavin Diamonds online because they have ALL of their signature collection stones in house to view prior to them being shipped out.
Go to their site or give them a call.
www.briangavindiamonds.com
I would never in a million years go to a store to buy a diamond because there is a HUGE markup vs. online sales.
I got the "Tiffany" setting and everyone thinks it is a Tiffany Branded ring, so that is not true that ONLY Tiffany makes a setting that looks like it is from Tiffany.......
mine is identical. Even when I wore it to Tiffany, the sales rep asked me if I wanted it cleaned and they only clean Tiffany jewelry at Tiffany.
Additionally, Tiffany's cuts are not all that great sometimes. I know their marketing ploy is that their diamonds are the "best" cuts, etc. but it is simply not true.........people that are educated about diamonds can look at a Tiffany grading report at the angles and percentages and they will know the diamond is not what it is hyped up to be. Sometimes the angles are incorrect and definitely not ideal and you can find a MUCH nicer AGS or GIA stone for less money online than at Tiffany.
Go on the Pricescope forum to get SUPER educated on diamonds. You will learn an amazing amount about diamonds.
Additionally, the setting you are talking about is probably going to be around $2k just based on platinum and the custom work that goes into it. Unless you can find the setting already made.......but I still think for a diamond band and a halo, it is going to be over $2k. 1 ct. at Tiffany starts at $9k according to their website.....which IMO is ridiculous.
These stones will be stunning just as an example in your price range! Additionally, unless you live in TX, there is no sales tax. Their performance blows AWAY any Tiffany diamond:
http://www.briangavindiamonds.com/diamond/diamond-detail/?product_id=AGS-1040399230025
http://www.briangavindiamonds.com/diamond/diamond-detail/?product_id=AGS-1040399230028
http://www.briangavindiamonds.com/diamond/diamond-detail/?product_id=AGS-1040397620002