It’s done because otherwise we get rounding errors when users buy more products;
the product is 16 with 20% tax. If i enter the price as 13,33 and user purchase 10pcs, it’s calculated as 13,33 (exvat) * 10 (pcs) * 1,2 (vat rate) = 159,96 incl. vat
if i enter the price as 13,3333 * 10 * 1,2 = 159,9996 rounded up to 160; which is what i need.