Tinned fish, port in Lisbon?

The port will be no problem. But, I have no idea about prices. Of course, there is a huge variety of prices and quality of port.

Sorry, but I’ve never noticed the tinned fish at the airport, but I have never been looking. You might be able to look at the airport website at ‘shopping’. There are stores in a number of places in the area that are really just tinned fish. They may have one at the airport.

Prices are usually higher at airports than at supermarkets. I have no idea what is available at the airport, but it’s generally mass market stuff. Prices and quality vary significantly - from a few euros to hundreds of euros. White, ruby or tawny? Do you want a vintage bottle?

The benefit of buying at the airport on your return is that you can then carry it on Duty Free and don’t need to pack it in your checked bag. I have had a disaster when a bottle of port didn’t survive the journey home in my checked bag and shredded all my clothes, despite being packed in an inflatable sleeve. You will need to be at the airport by 8.45am latest, so you aren’t going to have any time that day for shopping on departure day.

You can’t buy bottles in the city and take them on the plane as hand luggage.

Tinned fish is compact, relatively lightweight, and hermetically sealed: I would buy that in town in Lisbon. France has some very good brands too; La Belle-Iloise has stores all over the country.

Port makes more sense at the airport due to the weight and the risk of breakage!