The article mentions sales/VAT/IVA tax. Perversely I think the US actually does this right:

In the EU, VAT tax is included in the displayed price while in the US, sales tax is not. As the article mentions this is convenient for EU consumers who clearly know the price of their purchase in advance.

But I think it has a bad side effect: consumers do not notice the size of the vat/sales tax as strongly and as a result, I conjecture, there is less resistance to hikes in that tax (which is roughly 20% now). Being a regressive tax, it is quite uncharacteristic of the EU. So I conjecture it may have gotten that high partially because it is not annoying consumers at every purchase.