The way we currently add tax is non-standard for a lot of people and I think that in the future we want to switch to the way you described as the default, but I'm not sure when we'll begin rolling that out.
The current method will still be available I hope. I for one don't think it's creators responsibility to take the hit for countries deciding to roll regressive taxation and doing so prevents people from being irritated with their government for doing such things which they absolutely should be.
I'm not sure yet, in some countries it's very confusing and "anti-buyer" to have tax added on after the fact, especially when they feel like they have to pay more to get the same game.
