In my 30+ years of GMing, I think I've had players purchase the following for me...
1) Gifted me a subscription upgrade to Roll20 as a thanks for running online games.
2) Bought me a digital copy of Dragon Heist on Roll20 because he really wanted to play it.
3) Gave me a dragon mini that I could paint and display to commemorate a memorable encounter.
All of these purchases have been in the approximate past 2 years.
The expenses that no player has given me...
1) Countless rulebooks that I've purchased to find the system they'd like
2) Miniatures to represent their characters.
3) Adventure modules (of which I'm sure I've purchased hundreds - maybe thousands if you could PDFs)
4) Dice, gaming mats, pencils, paper, gaming table, and other accoutrements
5) Paid for convention attendance or registration for events (though I have chipped in for others)
I am a DM, and as foolish as it sounds, I take it seriously. I do not ask my players to provide any of this stuff, only their attention, involvement, and desire to play the game. I love the game and entertaining my friends.
So when I buy an adventure module, whether it's a $10 PDF, $40 Roll20 module, $50 hardcover, or whatever, I'm investing my time and potentially my friends' involvement in that adventure for sometimes 6 months (or more). I give it a lot of headspace - reading, planning, etc.
It's more than money to me. It's not just buying a novel or going to watch a movie.
The designers ask for our imaginations, to live in these worlds, to interact and care about the characters in a way deeper than you do at the cinema.
I have a feeling if you're on this board that you agree with me. I hope you do, anyway.