Slightly off topic, but, I grew up on the sw coast of the UK, when I was a teenager having a few beers and the walk home usually involved stopping off an a fish hut, and grabbing half a dozen oysters for about £1, a by product of the small boats bringing in their catch.
Fast forward some years (more than 30 but less than 80), and the cost of oysters is astronomical, add to that we export more odd seafood to the continent and the far east, and countless governments want to abandon or fishermen, literally up the creek with out any paddles!
I've lived on the med for a while, and whilst you do have to pay a bit more for the 'proper' stuff, it is more than worth it.
I personally think, that sea food in this country is highly underrated, we have some of the best available in the world, and we do even get the odd bit turning up.
Proper sea food, is and should be expensive, it takes hard work and is incredibly dangerous at times to be out in all weathers, risking life and limb for pittance and then be double screwed over by the government.
Love tuna, and the stuff in olive oil is yum, hate octopus and sea urchin, cockles, mussels, oysters - meh! teenager fast food for me!
No one would question the OP for making a bit of expensive steak go a long way, by adding extras.