It doesn't matter what the market value of a fish is unless you plan to breed them yourself. I wouldn't count on making money breeding them unless you've had success doing so with a less valuable fish. If you have a lot of snooty aquarist friends, and being able to show off a rare fish is important to you, do your research on the fish so you have plenty of snooty things to say about it. Your non-aquarist friends won't know or care, they just want to see movement and color, maybe size. The only other reason to pay a lot of money for a fish is personal fondness that makes it personally worth it, and no-one else can tell you how much your personal fondness is worth.