Welcome to the club

AC/DC is a pretty solid pin, no real issues with it. Some of the early premiums had a 'cloudy' window to the lower playfield which was then rectified in later editions. Other than that I can't think of anything special to look for.

If you buy a HUO or used one, it would be good if it had shooter lane and kick-out hole protectors as those areas of the playfield can be prone to ball damage. I'd also look for a one with color DMD, shaker, lit flashes and cannon mods since those add to the game tremendously (IMHO)

Good luck buying your first pin, AC/DC is a great choice and pinside will have your back if you need any help with it

Color DMD is about $500, shaker motor couple of hundred more. Both are pretty easy to install, but if you've never done any work it can be a bit slow and nerve wrecking