Amazon shows a 43% price difference in the same item shipped to the same address, but to a different account

Internet Archive founder Brewster Kahle (who also founded the company Alexa, now an Amazon division) ordered a pack of Sharpies from Amazon using the Internet Archive's business account, then, minutes later, ordered another pack using his personal account, both to be delivered to the Internet Archive: the order for the Internet Archive was priced at $8.63, while the personal order was priced at $12.37.

According to Kahle, the price difference is a feature, not a bug: businesses who pay extra for Business Prime ($179/year versus $99 for non-business Prime) get significant discounts on some items. (see update below from Amazon)

I have Business Prime and I see the price as $12.63 whether in a logged in tab, or in private browsing mode.

Update: Lori Torgerson, Amazon spokesperson, clarified that "business-only prices are exclusive to all Amazon Business customers, regardless of Business Prime membership" and "businesses of all sizes can register for a free Amazon Business account."

Below are the receipt for the Internet Archive, offer to me, and offer to my home business account (same price as the Internet Archive). Turns out I stumbled upon “Business Pricing.” It’s a “feature.” Business Prime costs $179/year, as opposed to consumer Prime for $99/year. Charging Me 43% More Than Another Customer [Brewster Kahle]