Why isn't USPS Regional Rate Box B included in shipping options when listing an item?

[blue_skies150]

eBay finally added USPS Priority Mail Regional Rate Box A ("Regional Box A") as a shipping option for use when creating a listing or shipping policy.  Why isn't Regional Rate Box B also available?

[nobody*s_perfect]

It took eBay about ten years to get the Regional A box in the shipping calculator.  They didn't have a good explanation about why they didn't add it sooner, and they also don't have an explanation about why they didn't do the B while they were putting in the option for the A boxes.

The sellers' clamoring for eBay to put the Regional boxes into the shipping calculator escalated in 2019 when the new USPS rates no longer conveniently matched weight-based rates which had been an easy workaround.

[johnrj1226]

Have always been able to buy Regional A & B Box label through eBay since the day they were introduced by USPS in 2011.  Used very few B boxes as we rarely ship heavy items.  Never used the shipping calculator.

[nobody*s_perfect]

The Regional boxes were added to the label-purchasing process very soon after they were introduced.  But they weren't available in eBay's calculated shipping when setting up a listing, until eBay added the A boxes some time within the past year or so.

Sellers who do use calculated shipping really needed the Regional boxes option, since they can make a huge difference in the cost for heavier shipments, and the weight-based workaround conflicted with international shipping.   Postage for the Regional A boxes ranges from $8.08 to $12.50.  Even for a 2-pound item (for which a seller wouldn't use a Regional box) the domestic online postage cost can range from $8.04 to $11.59, so setting a fixed postage cost inevitably undercharges some buyers and/or overcharges others and many sellers would choose to set up calculated shipping.