As long as you don't have any new product FOMO, this is an excellent opportunity for bargain hunters. Retailers and businesses enjoy discounts on older models right after the launch of a new model! This is also the Horizon model, which is usually more expensive than the base 3rd generation model due to its completely round shape. Since Oura comes with a $6 monthly subscription to unlock all features, a discount on hardware can help ease some of the hassle. However, Generation 3 will not last forever.
Even if you have FOMO, you won't miss much. I've used the Gen 3 for the past three years and tested a number of competitors – in my opinion this is still the clear winner. Compared to the new model, the only things missing are flatter sensors, a larger dock and a slightly more comfortable form factor. The newer Oura Ring 4 does have an updated algorithm that's supposed to be more accurate, but functionally you still get the same metrics with the Gen 3.
However, if you don't like the idea of a monthly subscription at all, my second favorite smart ring is also on sale. The Ultrahuman Ring Air is also 13 percent off on Prime Day at $305 and is a good choice if you're focused on training metrics.