Help understanding archive storage cost estimation

[lambHeft34]

I'm using a little less than 2TB of regional, archive-class cloud storage.  When I use the estimator it tells me that this should cost me a bit over $2/mo.  However when I look at billing (a little less than one month of usage), it tells me that this storage is costing about $21/mo (free promotion is in effect currently).   I'm a bit confused where the discrepancy is, any ideas?

Export from the console to confirm the above:https://ibb.co/42vVRp8
https://ibb.co/fkp0Ky4
https://ibb.co/9nNFT08
https://ibb.co/7kZ6t64