From the #RPGaDAY2017 challenge (info here):
What is the best source for out-of-print RPGs?
In PDF? The internet. For a singular particular source? DriveThruRPG.com. Of course, I prefer books in print (even out-of-print books) and rather than using eBay or Amazon, I prefer to shop in person. Now that I don't make it out to Missoula as often as in my childhood, the best place to pick up old books is my local game shop...same one I wrote about in my Day 10 post.
Huh. That one was pretty easy. Perhaps I should write about something else.