I bought a stuck case remover, years ago. After seeing it, I probably had everything that I needed in my toolbox. This was before PC's and the Internet, and I had never seen one, and had no idea how they worked. It came with a plastic box, just like reloading dies come in, and I still have it. I have added a larger drill bit and a 5/16 tap, for a case that I REALLY stuck.
Stuck cases are usually due to a lack of lube. A loose fitting shellholder can also contribute. A little lube on the inside of the neck will help reduce case stretch when you drag it back over the expander ball.
I would go ahead and either buy a stuck case remover or assemble one. Its sort of like an insurance policy! It also never hurts to have a few spare decapping pins and even a spare expander. It seems like I only have these problems when I'm on a tight schedule. Lightman