All current iPad models all run the same full iPadOS.
All current iPad models all use either the 1st or 2nd gen Apple Pencils.
So, iPads are more like cars, now.
You are paying for iPad optional features, now.
Do you want/need larger internal data storage space for data, like music. movies and photos/images and room for other types of data?
Do you want/need a bonded, laminated display?
Do you/want/need higher color gamut display with Tru-tone room brightness calibration?
Do you want/need faster internal CPU?
Do you want/need more internal RAM?
Do you want/need better iPad cameras?
Do you want/need better/more iPad speakers?
Do you want/need the improved, 2nd gen Apple Pencil?
Do you want/need to have the new Magic Keyboard portfolio for the 2018/2020 iPad Pro models?
All of these options are what you need to decide if you really need, or not, and to decide to pay for accordingly.
The more iPad features you decide you need, the more you pay.
Best of Luck to You!