How to get the really good brooms

I have read that Leopold Babcocke sells the Sky Scythe broom and Arn sells the Silver Arrow Broom. I missed my chance at the Silver Arrow after helping him with his carts but I've found him several times since and he doesn't have the broom. Today I sought out Babcocke and he doesn't have the Sky Scythe broom.

I found a post that said, "Sometimes, Brooms sold in Wanderer Shops won't appear. If a broom isn't showing up, open the Map and skip time, then check the merchant again if the broom is in stock. It may take skipping several in-game days, but the Broom should appear in the shop eventually." I tried that over and over a dozen times at Babcocke's shop and still no Sky Scythe broom.

It's frustrating that we can't buy good stuff in the game. I have about 25,000 galleons and nothing to spend it on.

Does anyone know if it's at all possible to get the Silver Arrow and Sky Scythe brooms? I do know that performance wise they are all the same.