In general; a $2 cup of coffee in north america costs 2€ in Europe. A $300 Wii U in north america costs 300€ in Europe. The only time currency conversion matters is because you are converting between two currencies, when buying a product from another country. GOG.com sells all their games in north american prices because it only has offices in north america. You are buying a product from north america when you buy fr…
We do in the UK, if you're a VAT-registered business.
For example, let's say my business pays $100/month for Web hosting in the US (or even the £40/month I pay to Adobe for Creative Cloud). I then have to "reverse charge" $20 of VAT to my accounts but then also claim back $20 of VAT from the tax authorities.. so it's a net zero result, but we still "paid" it.
I don't believe this applies to regular citizens though, but I could be wrong.. if it does, I know no-one who does it.