Exactly, except in this case it's more like paying $80 for a 15 year old N64 game when you can see the original price of it new was $60. And as you said, you could find a physical copy for much less.
Digital comics, especially older ones should be cheap so that they can be impulse buys. They would sell far more that way. Win win.
Recently drew a cover for a completely digital comic on comixology:
http://www.comixology.com/Digital-We...ics-series/500 Not out yet. Will be issue 6, 7, or 8. But they're all 99 cents new. Not that I get any money from the sales, but thought I'd mention.