In our shop we set it all to EUR on the back end and have set Printful to EUR as well. But when we set front end to SEK and place an order, enter Sweden and Zip Coe at ESTIMATE SHIPPING AND TAX we got no tax and shipping cost of only 4 sek. That's 0.4 EUR
We have set a product in Printful to retail price 19 euro ex tax but it shows on our product listing on the front end of our shop as 14,45 euro. Exactly only 1 EUR above the price we pay.