Doesn't need to be a conspiracy, where somebody is getting rich at the company's expense.
At work we have something similar, where every few years the IT department tenders the 'preferred supplier' for general IT stuff. The logic is basically that by promising the vendors exclusivity, they will bid lower. So yes, sometimes that means we'll pay 3x for a keyboard compared to the price we'd pay at the local discount computer store; I think in general the prices for the stuff that is in the 'tendering portfolio' is very competitive, otherwise it's list price.
OTOH, we save money since the billing from the preferred supplier is worn-in standard procedure, and also employees don't waste company time searching the web for the cheapest/best/whatever keyboard.
If you have a business account, everything gets bundled into that account. Sure, if your org is 110 people big, keeping track is pretty easy. My last job was with a state university. They see thousands of purchases a day, and Amazon bins them onto 1 credit card, and in 1 account. For all 8 campuses and over 50k people.
So the preferred vendor means also integrating with your financial system. So budgeting is easier. But Amazon makes this so damned hard. Even being able to tag purchases would help. But I'm sure ol Besos figured out that makes him lose a dollar.
With Amazon in Europe it's especially bad because if you accidentally buy something from an FBA vendor, you won't get a proper VAT invoice. And this makes accounting a pain in the ass.
Every other online store sends you a proper invoice. But FBA vendors will send you sketchy invoices that make it clear they aren't paying their taxes. Which is bad, because that means as a business customer you're on the hook....
At work we have something similar, where every few years the IT department tenders the 'preferred supplier' for general IT stuff. The logic is basically that by promising the vendors exclusivity, they will bid lower. So yes, sometimes that means we'll pay 3x for a keyboard compared to the price we'd pay at the local discount computer store; I think in general the prices for the stuff that is in the 'tendering portfolio' is very competitive, otherwise it's list price.
OTOH, we save money since the billing from the preferred supplier is worn-in standard procedure, and also employees don't waste company time searching the web for the cheapest/best/whatever keyboard.