It's definitely unusual to get fired without warning like that, even in the US. I thought it was fairly unusual to get fired at all, even with notice (except when the company has to do layoffs, or you fail a drug test or something). Most companies I've worked for would never fire someone just for being too slow (or even for complete incompetence in some cases).
@TheRubyWarlock said:
And lastly, pay seems to go up/down depending on the business in question - some offer peanuts for work that would cost a lot of money because they're A) cheapskates and B) think they can get someone to work for that amount.
I think it's totally reasonable for companies to pay as little as possible according to what people are willing to work for. That's what the free market is all about. I don't see any reason for the companies to pay more than they have to for the same amount and quality of work. (But in general, companies have to pay well, because if they didn't, no skilled employees would ever stay with them.)
And for the record, I think most CS graduates at my school could learn the system you described within a month, and it's pretty normal for companies to expect you to learn on your own without formal training. But if your manager fired you without ever trying to help you or even warning you that you needed to improve, he's definitely not a great manager.