[JumpCrisscross]

> you don't have to put in your address, just your country

In America, you would. Various municipal and county lines can create separate sales tax obligations based on address. Even barring that, I would find it intrusive and absurd for someone to demand my state of residence prior to even being shown price. (My IP address only loosely correlates with my residence.)

But again, that’s a preference. One most Americans share. Multiple equilibria.

[brewdad]

You keep saying it's a preference. It's not my preference but it's become something I've been conditioned to accept like not being able to know what a medical procedure will cost until after I get the bill. That doesn't make it preferable nor desirable.

[boring_twenties]

That is a completely bogus comparison. You can easily determine the total cost inclusive of sales tax yourself, and you almost certainly know your own local tax rate already. You cannot determine the cost of a medical procedure ahead of time no matter what you do, even to within an order of magnitude.