Quoted from Jojo1111:

As an ACDC Pro owner, I would put the value at high 3's for HUO at the moment, primarily because the ACDC game (Pro/Premium) seems to be (no official numbers here) one of the most produced Stern titles in the last 7 years (possibly of the last 15 years???) and the market is flooded with all the different variants of the game. In 3-5 years and longer, long after Stern has stopped making them, I'm sure the price will go up. Feel free to laugh at me, but I see ACDC (overall, not singling out Pro or Prem or LE variant) as this era's Addams Family (flooded market back in the 90s, now it commands a premium to own a good example of one). ACDC seems to be uber popular, everyone loves the game, all the collectors seems to have one, lots of locations that have pinball seem to grab one (and Stern keeps making them, seems like ACDC has been on the line fairly regularly since it released 2 years ago) . Market is flooded, as such the price remains low. Wait a few years and the price will most likely climb.
But yeah going back to your original price check, I'd say Pinside price on a Pro is maybe 38ish, add a few hundred bucks on top for shipping.
People also don't like the Pro as much as the Prem cause of the face and perceived inferiority, even though the rules are all there and it's an amazing game in its own right (and Aurich's decal really improves the look in that department if you don't like the original face). Again, in a few years price will prob go up, but for now the price is low.
Oh and OT but to the original poster, if you're a local, feel free to come to my IFPA tourney in a week and a half, we can discuss this further
http://pinside.com/pinball/events/arcade-odyssey-pintourney-2014-2014