YOu are so lucky you get store credit! I have to beg lfs to take my extras. I have too many, currently, alas, don't know what to do w/them!
What I like...I love the colors. They reproduce so quickly you really see how odd genetics are at work...strangest combinations. My favorite right now is a male (parents ...one yellow cobra, and a female w/icy periwinkle fins) who has a half black body, bright yellow lips, a peach/yellow/orange dorsal fin and tail with blue specks all over the front half of his body.
I definitely like them for their color and that they are easy to keep!