American Reloading has Barnes TSX .375 300 grainers at $37.49 per 100 after their 25% promo code, SHIPPED! This site normally sells pulled bullets but these ones are new! I picked up a bunch for "plinking" at just over .37 cents a bullet. They also have some .458 bullets in stock but are pulled and don't seem to be the ultimate deal.

https://americanreloading.com/en/314-375-h-h

-John