Bidding on this site, the buyer’s premium is 25%, Spanish IVA included, and there is no VAT on the hammer price and no card fee: at the starting price of €400 the total is €500; at the low estimate of €600 the total is €750; at the high estimate of €800 the total is €1,000.
Through LiveAuctioneers, Invaluable, Drouot or Bidspirit the premium is 30%, so the same hammer of €800 costs €1,040 there. Shipping and insurance are quoted separately; the estimator on this page gives the figure for your country. Buyers outside the EU pay no Spanish tax on the lot; the destination’s import rules apply (United States: original paintings and drawings enter duty-free; United Kingdom: 5% import VAT on art). Card payments are accepted up to €10,000; larger amounts by bank transfer.