That $50 is not what you actually pay. You'll find another 12 or so fees and taxes on land lines and cell phones which can add up to another $10-$15.
One which really rankles me is the telcos charge a fee to comply with the law. Tmo currently charge almost two dollars a line per month for that ("Regulatory Programs Fee"). I kid you not - the fee literally is for them to comply with legal requirements. This is all a side effect of the regulatory capture of the FCC.
Here are the taxes for California http://www.mywireless.org/state-issues/california/ - and note that doesn't cover federal taxes. You can see a sample tmobile bill on their support site - http://support.t-mobile.com/docs/DOC-1101 - and notice the section at the bottom taking up almost a quarter of the space is the taxes. They didn't include their fees in that example either.
If you do a prepaid plan instead, the taxes and fees are included in the price. When you sign up for the $30/mo 5GB plan and get your bill, it's for $30, not $30 plus a bunch of other things.
In Lithuania, Europe, I spend about $9 for this (even more, with 1GB of data). Very happy about the competition between carriers in our country - it is constantly making everything better and cheeper.
They don't. You pay for roaming. However, in summer 2014 there will be no more roaming charges for the EU (forced by the EU commission on the carriers - the carriers were playing dirty all along, e.g. TMobile and Vodafone have companies in many EU countries, but customers still pay roaming charges in "different" networks provided by different subcompanies). This still won't mean free mobile for the whole EU, as most networks only offer free calls/texts/data in their local networks, while you have to pay a little if you're in another operator's network (in the same country).
Thank god I live in Europe (in the UK, the equivalent costs about 20GBP per month).