http://www.royalmail.com/portal/rmI reckon this seller is choosing an insured and tracked international service.
This is a wise precaution, as it can be tracked and when the parcel arrives the seller KNOWS it has been delivered.
I have been ripped of by a buyer who insisted an 040 card didnt arrive. He raised an issue with ebay and paypal. It was a real mess. Later I saw him sell the same 040 board on ebay!!!!
Here is an example of postage to Italy from UK for a 0.75kg parcel 15x15x25cm. It will cost £34.99 tracked using Royal mail global priority.
http://sg.royalmail.com/portal/rm/PriceFinder?catId=23500532&gear=pricingcalc