No way to know the true number. I had one that I sold last year and still have a copy of the sticker. A/C was a $631 option on a 1981 Scrambler. Compare that to $2,399 for the Sport (SL) package and $409 for automatic transmission. Total sticker on this one was $11,572.
This is what I don't get. A/C sounds like a nice option, and I use it all day, every day in my DD for about 8mos out of the year here, but it would be absolutely useless in my CJ8. Might as well buy a pack of ice and lay it on my lap.