Re the issue of the prices charged for things like apples etc.--see my post Imagining the Fate of Copyright in a Future World.
Imagine 1000 years from now, if we still have these ridiculous IP laws .... Say you need some music--to play in your department store's elevators, to go with a scene in a movie, etc.--you can choose between an almost infinite supply of older, public domain work, or pay for a new tune that is still under copyright. That will force new works' price to be almost zero.
One concern I have is that the IP socialists would at that point come up with a new IP right--basically a renewal of copyright held by someone who "rediscovers" older work forgotten in the almost infinite pile of public domain work. Imagine living in a world where Michael Jackson's work, or the music of the 70s, had been basically forgotten and lost, a needle in a haystack, surpassed by all the music over the ensuing centuries ... then some DJ starts playing it, people rediscover it anew.. shouldn't he get credit for this? After all, it takes a lot of work to loook thru all the old stuff and find "what to recommend" (a lot of IP law is based on the Marxian labor theory of value, the idea that you should be rewarded if you labor on something, as in the old "sweat of the brow" copyright law doctrine). Shouldn't the discoverer be rewarded for this? After all, if he's not, you consumers would never have heard of Michael Jackson, would not have the pleasure of knowing what (free) tracks to play at your party. What's the harm of awarding the DJ a monopoly? After all, you would never have found that needle in an infinite haystack, so no one is worse off, and everyone is better off. Copyright can never die; it only gets reincarnated. O brave new world! That has such laws in't!