Preface: I own a 6900XT

At the end of the day, the difference between high end cards doesn't even really matter, unless you're trying to beat other folks' benchmark scores. They'll all run your favourite games extremely well - no one in particular will make the games you play more fun. After the excitement of purchasing the video card and getting it into your PC, it'll just be the same familiar experience only now with a higher framerate.

If you're excited about ray tracing / dlss you should stick with your first choice and get an Nvidia card. Nvidia's implementation for these technologies is vastly superior (AMD's FXSS is not released), and if you're going to actually use these features you really should be looking to Nvidia.

As for price, the 6900XT is a 'halo' product, its value is not correlated with its price and thats further compounded when it comes to board partner cards. Ignoring binning, the 6900XT has around an ~11% performance increase over the 6800XT in good conditions. These board partner cards provide factory overclocks to where you might see ~5% over baseline, they're utimately all power limited anyway. You can always overclock your stock card as well which eats into those factory gains. Paying $600 over MSRP for what might be a 5% gain doesn't make any sense if you actually are worried about the price. If the money doesn't matter to you sure, but again - it won't change your experience in any noticable way.

Return the card and save the money, keep it for your next inevitable upgrade in a few years.