[Dr Colliebreath]

Sorry to hear about it. Unfortunately, it is part of the hobby. It sounds like you did everything right.

The fish probably was damaged in capture or transport and doomed well before you bought it. I think fish that die within 30-60 days of acquisition in most cases weren't going to make it anyway (assuming they were handled properly by the hobbyist, which is clearly the case with you).

The ones closer to 3" do seem more resilient.

I wouldn't necessarily let this stop you from taking the plunge again sooner rather than later. You want the fish, saddlebacks typically are hardy for butterflyfish, and hopefully you will get a good one.

Do you know where your lfs gets its fish? If from Quality Marine, that is good. If not, you might try an online vendor like the regular Live Aquaria or their Diver's Den operation for more sensitive fish like butterflyfish. Their fish come from QM and seem to do very well.