Some countries and jurisdictions (usually USA, sometimes Australia, China) require eBay to collect import tax from the buyer when they pay for their order. Consignments where eBay does not collect taxes may require buyers to pay additional import fees (e.g. VAT and duties) as part of clearing their parcel through customs, or when they receive their order.
Buyers are responsible for paying import charges. For international postage, I can't include these costs in the item's purchase and postage price. You have to be aware of this.