Lowest I've ever seen this. Other process prices seem to be holding despite the 3000XT parts announced.
https://www.microcenter.com/product/616858/amd-ryzen-9-3950x-matisse-35ghz-16-core-am4-boxed-processor
It's going for $420 at other e/retailers, as seen here.
https://www.microcenter.com/product/608316/amd-ryzen-9-3900x-38ghz-12-core-am4-boxed-processor-with-wraith-prism-cooler