Honestly there are kind of like discus, you breed a ton and sell a ton. Totally unlike FH where your breed a ton, cull a ton and sell a few. Angels and discus it doesn't seem to matter on quality as much as it does with quantity. Discus are the major $$$ maker of the 2, it's just 2x as hard to take care of them. Angels ppl don't seem to care so much about color as they do with the fins, most ppl want the really tall luxurious fins that stick up straight, it's harder to sell the same color angel with bent over fins. Also if you want a good $ maker angel make sure it's a blue or albino. They tend to go for about $5-10 more then any other color.
