It would be nice if Itch.io showed the prices including VAT on the store page for EU-customers either as default or with a toggle.
If i go to GOG, Humble Store and Steam they all show the prices with VAT included, the price i see on the store front is exactly the price i will pay. Not so on itch; here i'm shown the price without VAT, press continue a couple of times and then get the final price that is now 25% higher (Swedish VAT) than i expected. That means the value proposition changes. I now have to convert the new sum total to my local currency, then compare it to prices on other stores and all of a sudden itch is more expensive, showed me the wrong price to begin with, wasted my time and in the end most likely lost a sale.
I know this is handled differently in the NA but in my country and most of EU the prices are shown including VAT. It is convenient, it is how other stores do it and it is what the customer expects.
I don't know exactly how you should solve it but you do have the VAT-information from the user profile, maybe you can use that and if it's a EU-country show prices with VAT? Or even simpler just a toggle on the profile, inc / excl VAT? Some way is preferable to none.