I was at the PHoF for the first time this last weekend. Amazing selection of games (Pinball Circus! Wow!). Prices are fair — 25c for old games, 50c for 80s/90s games, 75c for modern games.. and almost all 3 ball games are set to 5 balls. Played 36 machines in total.. most were 80/90s machines that I've never seen/played before. I put in 7 hours and only spent $35. Pretty good deal, IMO.
The conditions of the machines varied greatly. Some were in immaculate condition.. KISS, for instance. Some were beat up and no fun to play.. Star Wars was one. Lots of weak flippers, dead switches, etc throughout the place. I'd guess about 20% of the machines were switched off. Tim was busy fixing machines all day, so I just came to assume that there is no way for their limited resources to keep up with the wear and tear on the machines.
I'd definitely go back next time I'm in Vegas. Despite the maintenance issues, I had more fun there than in the casinos and my money lasted way longer.