Woah, that's a lot of Quoy's!
$33-35 is a price I've heard several times for Quoy's that are mislabeled as princess parrotfish - but I've never actually seen a princess in a LFS for less than $55 or so.
I've messed up too ... spotted a lovely 4-5" Achilles tang at another Petco, and brought it home - only to discover that it brought some velvety little friends along with, which are now hopefully choking on the copper in my QT. Lost the tang, in spite of a freshwater dip last night. Curses.
To date, the princess is snacking on bits and bobs here and there, but the Quoy's is still not eating that I've seen - and I'm sure the CopperSafe in the tank isn't helping.
~Bruce, hoping that everyone else's parrotfish give them a _lot_ less trouble than this one has given me!