Sorry, can’t tell how the prices are in America. But for Germany this kind of deals are around pretty often.

OneDrive with Microsoft 365 Family subscription. There are several deals for 50€ per 15 Month for 1TB per Account. Since it is the family subscription you’ll get up to 6 Accounts. So it is 3.33€ for 6TB or 0.55€ per TB.

Can you give an example where this is done?

Not in Europe