Dragging this back towards a HN topic, years back this caused a fight for PC computers stores. They argued that their main customers were businesses and so advertising prices "before tax" was expected by the trade customers. Others argued really most customers were hobbyists and so would pay the VAT price.

Obviously it's beneficial to be able to advertise the lower price, these days assembling your own PC from components must be much less common than it was back then so I imagine even if the decision went in their favour back then that's changed since.