Or, try apples in a place that actually grows a large amount and diversity of apples. In season, you can walk into some grocery stores and find 20+ varieties that all actually taste unique.
But, there's a variety of pineapple you can only get only in Hawaii that's way better. And I've only ever sourced really good key limes from friends and family trees in Florida.
Store bought tomatoes are also usually shit, but you can get ones from the farmers markets and road-side stands.
NC has a bounty of fruit and vegetables available locally grown:
https://content.ces.ncsu.edu/central-north-carolina-planting...
https://www.businessinsider.com/japanese-melons-cost-price-s...
That said, the pricy melons are usually bought as gifts, not eating yourself. Compare with eg. high-end whiskey.
(I'm also pretty happy with $30 bourbon compared to what single-malts are up to these days.)
But you also have the problem that OP described where people literally have no idea what quality actually taste like so they can get away with selling mediocre fish. Nearly all fruit in the United States is another example. My cousin by marriage was born abroad and he absolutely refuses to eat his favorite fruit, mango, because so much of it is outright trash and even a "good"mango sucks in comparison