Cod is an expensive luxury now, because it is scarce due to overfishing.
This link shows fish prices at point of landing - Peterhead
http://www.caley-fisheries.co.uk/prices.htm
There was a time when oysters were the cheap food for the masses.
Cod is becoming a luxury food too.
If you had chosen haddock or plaice instead, you would have saved money
(I prefer haddock to cod)