I remember some epic-huge sets running about $100 when I was a kid back in 70's/80's. Some huge ship/moon base set and stuff. But those were rare (like one or two sets) and $60+ for a medium sized set seems the norm these days.
I wonder if part of the price hike is all the licensing these days. Anything remotely popular with the kids gets licensed by Lego: Harry Potter, Raiders of the Lost Ark, Batman, Star Wars, Lord of the Rings, etc. According to Wiki
, I see twenty-two licensed themes. All that costs money. Back in my day (old man) you had "Space", "Town" and it was a big day when "Medieval" came out and we could stop using antennae as swords. Speaking of, it seems like every set has specialty pieces these days that never existed back during the dawn of man. All that stuff has to cost money too.