A mutual on DA offered some for free! In retrospect, now that I know the real value of TH codes, I'm really glad I didn't have to pay anything for mine, haha :')
I saw a topic recently derailing while on this subject, so I figured I'd put a place to share freely!
I got mine from FlightRising, from a kind person who PM'd me after I showed interest in buying one of their characters c:
I got it for free off a journal from FA, and I'm glad. I can't do anything worth actually trading for a code so I lucked out :p