Go forward and get those guys in the right condition to breed them. If you get no more than typical guppies demand in your area, it will be just fine and you will profit a tiny bit. If there is a local demand, you may do much better than that. There is no telling until you actually have something to sell and you present it to your LFS. I would be tempted to give them a sample to sell and see how that goes. Until they have people asking where they can get those neat fish that they saw just last week, the LFS will probably not give you very much for them.