As someone who values a fish based on things that aren't just money, I'm of the opinion that yellow tangs were always worth a lot. What other tangs stay (relatively, for a tang) small, have amazing color, and aren't total ******s? Just because you could whip them out of the ocean like hotcakes, doesn't mean they should be worth squat. The only thing making a fish cheap does is lower how much the average person cares about said fish. Just think about how many people see fish like green chromis as disposable. Wouldn't you make more of an effort to keep your $160 tang healthy than the $50 dollar one? It's still an animal at the end of the day, but the money does have a say in things (like it does in everything else in life).
Also, all the people saying CB yellows aren't colorful like the wild ones haven't seen wild babies. Living in Hawaii, you can see that some of the babies are white, just like the CB ones. Plus, it has everything to do with environment and feeding. Here's a pic I took of the Biota yellows in our store before they were sold. Bigger one was maybe 1.5" but they got plenty of mysis, pellets, and greens every day.
I don't mean to rant, but the people complaining about the price of these fish aren't considering the value that these animals bring to our hobby on an enjoyment level.