I have a Schoolcraft flipper, and it has survived a few drops on hardwood and concrete. Still on its first elastic, has broken yet.
Repairing a flipper is easier than you think - I can email you a video on how it's done. It takes fewer than five minutes. I've fixed a Johnson one I had several times.
Don't have a Kueppers flipper, but I have a could of his shells and they're very good.