> There is no reason you can't show final price including tax on the label in a physical shop.
Sure there is. When the price label is affixed by the factory/warehouse then you would have to track where everything is going and be unable to share inventory. Also, if the sales tax rate changes then all the labels become wrong. These would ultimately increase costs for consumers.
Adding sales tax is also not at all misleading because the customer is not going to be surprised by it and there isn't going to be a competing merchant across the street who can avoid charging it.
There are also business customers with their own sales tax ID and they can buy things without paying sales tax when they're being incorporated into a product where they collect the sales tax themselves.
> There is no reason why a restaurant should be able to charge a 20% service charge instead of increasing regular prices by 20%.
This is actually true. A mandatory undisclosed fee is BS. But it doesn't help much, because if they want to do it then they just make it "optional" where the way to avoid it is more of an inconvenience than paying the fee.
> They can upsell you on additional services, but they can't suddenly notice in the last checkout step that your price is higher because the website you are using is charging a fee; that fee was known to them at the beginning of the transaction and should have to be disclosed at that point in time at the latest.
The last step is where you disclose your address. Before that they may not even know which country you're in, much less the city/state, and there are a thousand legitimate reasons to have different prices or fees in different jurisdictions.
> If you want to go even further you can also dictate that shipping and handling fees are only allowed to include reasonable costs of actual shipping and handling.
That doesn't really help, they're typically charging the actual cost. They just don't include it in the advertised price because it makes you inclined to make the purchase online instead of saving $10 by picking it up for the same price but no shipping charge the next time you go to the competing local store.
There's a reason Amazon's major competitive advantage is free two day shipping, derived from having the scale to achieve low shipping costs themselves.