My partner's iPad Air 2 is starting to act up - battery reporting is wonky (put it down in the evening at 30%, and in the morning it reports 50%, without charging), and especially when the battery is reported as low, the touchscreen is unreliable...
Getting the battery replaced is about as expensive as a refurbished iPad Air 2 (with no guarantees on the battery). She also has a quite decent Logitech keyboard which would be useless when buying a different model...
Decisions, decisions...
An 2017 iPad Pro 9.7" might fit into the keyboard case - same dimensions, but different placement of speakers and camera flash - but those are way more expensive (also refurbished), except maybe if you get the 32GB model. Her current iPad uses more storage, though maybe some stuff could be iCloudified.
The refurb iPad Pro only has 32GB storage, but the 128GB versions were prohibitively expensive. There was very little space left after restoring the backup from the previous (64GB) iPad Air2, but it seems iPad OS iCloudified a couple of things automatically and now it doesn't seem like it's going to be a problem.
Now pondering getting her a pen (which is supported by the 2017 iPad Pro, in contrast to the Air2), but those are currently about half of what I paid for the tablet 🤷♂️
...so I got an iPad Pro 9.7" from a refurbisher for a decent price, but it turns out the magnet placement is different enough for it to not stay fixed standing up in the Logitech keyboard case. (I assumed this might happen from a couple of old reviews, but tried anyway.)
So now I got a 2nd hand Zagg Folio keyboard for like €20🙄 ... It's way thicker than the Logitech case, but seems ok otherwise. It also doesn't power on the keyboard automatically, which will probably take some getting used to.