"Free" cooking oil

If you buy tuna or fish steaks in oil, drain it into a container and use it in stir fry or to fry potatoes or saute other foods. No sense in wasting it; it's good oil for cooking although it might have a slightly fishy taste, so be judicious where you use it.

Cheaper than canned salmon

Make a fish loaf or patties from canned jack mackerel or tuna instead of more expensive salmon.