I have only found them for sale at online aquarium suppliers. These are fish that are sold in groups of maybe half a dozen or so, and at ridiculously high prices.
However, that being said, if I can manage to get just half a dozen females to spawn successfully I should get enough logperch to grow out and be able to stock several thousand when the time comes.
That is the plan anyway.
Like I said, if the smallies eat the all so be it. LOL. Heck, for the prices that aquarium shops charge for these things I could make a small fortune LOL.