And you think the seller is pocketing inflation price increases? If you're really talking about inflation, there's nothing to pocket, because the profit after increasing the prices has the same buying power. And every other price increase is not related to inflation.
Inflation is a systemic issue that cannot be specifically identified. A tax is a deliberate fee that is distinct from the actual cost of items. Not showing the cost of tariffs would be a deliberate attempt to hide the price of that tax.