[erjiang]

Your question is hard to answer if you don't give some examples of what you consider "expensive".

Drawing tablets are now cheaper and higher quality than they have ever been. A quick of Amazon shows an "Amazon's choice" of a 6.3x3.9" tablet for 34 USD. That's a bit on the small side, but very usable.

If you are looking at flagship professional-level Cintiqs, sure, they are expensive. But that's like looking at an Apple XDR display and complaining that monitors are so expensive. I'll add that display tablets have multiple drawbacks compared with non-display tablets - nothing major for the occasional user though.