Originally Posted by
work2fly
I'm not sure I've seen any fish other than Tilapia used for pescado frito at our local tacquerias. Sometimes great, sometimes muddy tasting, and every so often we'll get one that tastes like ammonia (and never return)

It's been almost 10 years since I lived in Portland, OR, but at the time, tuna and halibut were the standards for fish tacos.
Back on the original topic, the idea that a restaurant would charge $30 for tilapia is still shocking to me, even if it was in a 5-star hotel.
The next time I see a dish labeled as "fish", I will be sure to ask what kind of fish. The problem with this approach is that most waitresses here have no clue (i.e. to them, fish is fish).