I recently purchased a refurbished iPad Pro + 1st gen Apple pencil via Amazon, which also wasn't my first choice but there happened to be a good deal that I nabbed. I feel like the OG battery is plenty workable already, even while I'm using it for fairly energy intensive purposes (in my case, illustration.) That said, between a protective case, the Apple pencil (which I did buy new, I would NOT get a used Apple Pencil nor would I get a knockoff version), and the iPad pro itself, PLUS taxes, I still spent something like $500 for the whole enchilada. So the benefit and convenience that the iPad brings to you should be worth about that much to you.
Things to consider about whether you ought to get an iPad:
- Would a cheaper tablet option work for your purposes? Or does the iPad serve exactly the need you're trying to fill? In my case, the illustration program I wanted was only on iOS devices, so I could only go with an Apple product.
- Is there another way in which spending several hundred dollars would buy you joy, convenience, or purpose in the same vein?
Things to consider about purchasing a used/refurbished iPad:
- Price, of course. The longer you wait, the cheaper the older generation models get. I think the first gen of 12" iPad Pros should serve you just fine for what you described, no need for additional bells and whistles. 1st Gen apple pencils have a tremendously stupid charging mechanism, but I think it should work for marking up music sheets fine in all other ways.
- Ebay vs. Amazon - mostly just make sure to check the seller's feedback, reviews, and what your options are for returning the device if you get a lemon. I have purchased refurbished electronics from both sites over the years and never had a problem (knock on wood.)
- Get a protective case that will hold both your iPad and has a slot for the pencil. They are sooo easy to separate, misplace, roll into little crevices or off countertops otherwise.