Molly fish cost $2–$4 per fish. Molly fish are generally inexpensive and easy to get, making them popular among beginner and expert fishkeepers alike.
With that said, the price of molly fish can differ based on the variety and coloration. You can get common molly types, such as common mollies, black mollies, and balloon mollies, for as low as $2–$3. Meanwhile, rarer varieties, such as red mollies and neon butterfly lyretail mollies, can be as expensive as $15–$20 per fish.