Blue Nile portal
 

I know this has been somewhat discussed before, but I'm wondering if anyone has found a way around the $7500 max for Bluenile cashback/rewards portals? I'm about to pull the trigger on something in the 30k range, and would like to maximize the return. I did run a search, and it looks like most info is from 2012 or older. I've tried to get local jewelers to match Blue Nile's price, but none of them can even come close...so a cash discount is out. Any help would be greatly appreciated. Have Amex Platinum, Chase Ink, SPG, and a number of other cards. Wanted to see if anyone has run this gauntlet before and what the best way to maximize rewards is.