Hi! I have the iPad Pro with the second generation Apple pencil. I paid around £1100 in total with Apple Care.
Life changer. I prefer to keep electronic notes rather than papers, but it is difficult as teachers will continue to be old school and give out handouts and expect you to keep a paper copy of your notes despite keeping a digital copy already. So you might think having an iPad is easier, but it really isn't as most likely you will still need to carry around paper and pens. But the great thing about using an iPad is that you have fewer notes to carry around. I use my iPad for digital textbooks, books for my coursework using the Kindle app, and basically just everything you can think of. Also, think about which app you will use to take notes and how convenient it is to study from and print out. I personally use notability and I think it's pretty decent.
Don't forget that you won't just be using it for note-taking! I usually use mine for leisure like watching videos at the most.
But definitely, the Air is worth the extra additional cost, but I truly recommend to get the Pro if you have the budget to, as it is unparalleled with how amazing it is for class notes. The Air is still amazing, but I totally believe it is a worthwhile investment.
If you're a person like me that prefers less weight and more convenience, then get the iPad. You will continue to use it for years and not just for note-taking!