I buy indie, art, and auteur comics in trades and hardback (e.g. Alison Bechdel, Craig Thompson, Ivan Brunetti, Chris Ware, etc.)
I have a pretty good library of the Comics Studies variety.
I buy mainstream monthly comics digitally. Right now I am follwong and enjoying “Trees,” “The Flash,” “Constantine,” “Black Widow,” “Ms. Marvel,” and many others. Yeah, it’s a $80-140 monthly habit doled out in weekly installments every Wednesday.