Ha! I actually do buy porn -- specifically erotica and educational style videos (I think I bought a Betty Dodson video last, and a book of erotic fairy tales). I like supporting the actors and authors. XD But yeah, it was months ago.
I have a God's Girls subscription and I'm pretty sure $5 comes out of my account each month towards it. Otherwise I don't pay for anything porn related. I would if I found some worth paying for, though! I like to support sex/body/queer positive porn. I'm looking forward to a future where that sort of thing is more accessible; I'll happily pay to support it.
I bought two new DVDs a little over a month ago. I usually refresh with two or three a couple of times a year. Usually it's a comp with 10-12 scenes or a 4 disc 16 hour set of themed porn scenes. Most of what I buy is to watch with my wife, but we only watch together twice a month. I may watch once a month by myself. I buy from a "marketplace" site, so it is not expensive.