In B2B nobody is intrested on VAT. VAT is an pass through position. On all B2B web-shops I know, you get shown prices excluding VAT on the product listing and for the accounting you get prices incl. VAT. It's partially correct to say " .. there is a EU law that says that all the e-commerce websites must show the price including VAT in every page.", but only for consumer-prices (B2C).

Why not a button were the customer can choose the price with or without VAT. When that's not possible at least a button for the programmer. I and a lot of other people needs this solution already from the upgrade of v9!