In my opinion the key difference between music distribution and movie/TV distribution is that the latter has access to multiple revenue streams.
You make a movie and you show it at the theatres and get money. You sell the cable/free-to-air TV rights and get money. By the time you release it on DVD you've (hopefully) made back most of your production costs or are even showing a profit already.
You make a record on the other hand and when it's played on the radio (the equivalent of free-to-air TV distribution) you don't get any money; in fact it costs you (in marketing or other incentives) to get airplay. You have to make back all your production costs via CD sales. Granted, it doesn't cost as much to cut a CD as to make a (Hollywood) movie, but then there are only limited ways to get your money back, necessitating a higher unit-charge.
If labels would be able to charge radio stations to play their music (something highly unlikely to happen, by the way) I believe CD prices would likely fall.