I remember it was expensive pre-deregulation, but can't remember numbers as my folks were paying in those days. My first flights out of my own pocket were in the '90s, I think I paid about $2000 to go from LAX to NBO, and not much more than that for a 3-stop RTW with lots of overland segments on *A. An open jaw from LA into Shannon and out of Prague was about $800 off-peak then. Not too different from today's prices, really, but they did go down significantly in the oughties before going back up.