Most new drives are sold into consumer/end user retail around $20/TB and only seem to dip a little during sales (with most sellers also quantity limiting any sales, also). Getting to $10/TB is possible but typically involves buying manufacturer recertified, and may involve going smaller (14-16TB drives) than you might prefer.

I managed to find 64x Seagate Exos 20TB for $13/TB new about 2 years ago, on NewEgg of all places, but I’ve never seen that deal repeat. :(

All the new 30TB+ HDDs using HAMR technology from Seagate and WD still feel like expensive unobtainium.