There is no US sales tax. You're thinking of state and local sales tax, which in most states (maybe all that charge a sales tax, I don't know) generally added on top of the sticker price. I wish it were included (when possible), because it can be frustrating -- especially to those of us who live in states that do not have a sales tax.
For taxes, in US eCommerce transactions at least, that generally isn't possible until checkout anyway you need to know where you are shipping the order to apply correct taxes. For brick and mortar shopping, I agree, taxes should just be included in the label price.
A breakdown into what part of the price is set by the business and what part is set by the government seems to fit your provided definition of “visibility”.
