Fresh vs. Frozen
Most fish are cleaned and frozen aboard the boat, what you are looking at in the fish section or in the case beautifully arranged on ice has often been frozen then thawed.
Frozen fruits and veggies are grown in season and likewise frozen when they are at their best.
My big tip to you is buy the bags of frozen fillets if tilapia, salmon, or flounder in the frozen food aisle and thaw yourself. It costs about 40% less and it’s only frozen once, so you get better quality.
If produce is out of season, frozen tends to cheaper than imported.