I know that there was a company that used to sell the radio shows and interviews on LP. They were very expensive back then, too. But that amount of $ is just crazy. I am sure that you can find someone that has a copy of it on CD on their trade site. I know that I don't have it.
The only LP interviews that I did actually buy are Stevie's 1981 and Fleetwood Mac's (Stevie, Lindsey and Mick) 1979 Innerviews with Jim Ladd and they were $ back then.