you just display the price with your local VAT. In the last step, if the user is from a different country AND if you do more than 100k eur revenue for that coun

you just display the price with your local VAT. In the last step, if the user is from a different country AND if you do more than 100k eur revenue for that country/year, you recalculate with the correct user VAT. And if you are Amazon, you then give the diff as a discount if it was more than advertised.