The following are prices at Jet Express, Malta Airport: pizza baguette (half a bread roll covered in white sauce), €4.90; two small bottles local still water, €3; stale Wudy sausage roll, €3.50; two ricotta pastizzi, €1.20.
The following are prices at Air Service, Bologna Airport: ciabatta (full ciabatta with prosciutto and mozzarella), €4.50; two small bottles local water, €2.80. It seems that water and bread and of course stale sausage rolls are very expensive in Malta!
I am under the impression that by law, prices must be displayed; at Bologna Airport prices are clearly displayed.