I'll give you the answer you're not going to want to hear, but this is usually the answer you'll be given: we cannot tell you how much you should charge; only you can.
$40-60/hr is not an unreasonable rate (at least in the US), as long as you can back it up with the quality of work. It also depends on what you're doing - I can get away with charging $100+/hr for the niche I'm in, but if I were to do HTML/CSS, it'd be a lot less.
Yes, yes they do. However you usually get what you pay for. There are exceptions... but I've generally found that the cheaper labor usually costs more because I have to have someone come in and cleanup & fix issues that came up.