Unlimited costs more, I don't pay it because I never use more than a couple texts a month on my personal phone. I'd rather pay 20 cents for a few messages, even though it's extortion, than $5 a month (25 messages worth) and only use $1.20. I can call anyone I know with a Verizon phone (everyone I care to talk to has them anyway) for free any time!
The carriers are taking advantage of the fact that kids and most adults don't seem to realize the value of money "oh, it's only 20 cents, that's nothing". Stupid consumers lead to higher prices, it's a simple fact.
Considering the extreme cost of wireless service to begin with, texting and internet should be included anyway; without the additional cost. But then the companies couldn't line their pockets enough to own 4 houses each!
Same thing with the music services, $15 a month is a lot for those services. It's a convenience vs cost issue and most people are too stupid to realize how much money they loose on conveniences.