Two 1 TB blocks on different backbones for $15: https://portal.usenetprime.com/cart.php?a=add&bid=37.

3 TB for $15 (4000+ retention): https://billing.blocknews.net/signup/blockfriday

6 TB for €15 (2800+ retention ): https://www.bulknews.eu/checkout?product_variation=43&locale=en%2F and use the code bf241. Bulknews is on Abavia backbone.

4 TB for $25 (4633+ retention): https://newsgroupdirect.com/member/billing/?plan=ce57&planid=233&yes_tracking=1

500 GB for 10.50 till January 3 (3000+ retention): https://usenet.farm/

The retention might not be accurate, probably larger.