The Chilean sea bass is a trendy thing to serve in restaurants (or at least it was a few years ago; maybe it's on the outs now), and fetches high prices, higher as it becomes scarcer and more endangered. But a decade ago when it was called a Patagonian toothfish it was literally a garbage fish, often thrown back by fishermen. It's still very cheap in some parts of the world.
Some cuts of beef were considered the "cheap cuts" until one recipe or another happened to make them popular. Skirt steak, for instance, used to be what you got if you couldn't afford better. Cowboys ate it because they sold the better meat to customers; they developed ways to make it less tough, and the resulting dish is now called the fajita, and its popularity makes skirt steak expensive. Even stew beef is now expensive.
Chicken wings also used to be almost a throw-away part of the bird, even as recently as my childhood. A wing is mostly bone, and what's left is mostly fat; they're messy and hard to eat. But due to the popularity of Buffalo wings and other recipes that followed, wings cost more per pound than thighs.
The most expensive bread in your local supermarket is probably a coarse, grainy "artisan bread" that would have been the cheapest, most plentiful bread available two hundred years ago. Back then, Wonder Bread would have been considered a luxury.
There are a number of other foods or ingredients about which the same kind of story could be told, including several kinds of fresh produce (like mango and arugula), some cheeses, even a few beverages. (I used to have a list but I can't remember most of them.) At one point, I actually heard about a trendy restaurant somewhere which was serving something that involved a premium bologna. Seriously.
If one went to a culinary hotspot like Manhattan and opened a restaurant where every single dish was built around something that was recently considered "the cheap stuff" until it became trendy, and maybe named it Chez Bologna (pronounced like the Italian city, not "baloney"), I wonder how well it would do.