There's tons of advice online about transferring money out of China, so I won't go over old ground. But I advise new FTs to ask for an official tax receipt at the end of each year (or well before you're about to fly out of the country). If your school drags its feet, go to the local tax hall (there's one on Funan Rd) and make inquiries.
ESL schools don't usually provide FTs with monthly payslips that show earnings and deductions, so it's murky. An *official* tax receipt proves that your employer actually has been paying taxes on your behalf. It's also necessary to have this proof in order to wire amounts over $500 out of China. Otherwise, you're gonna have to resort to more risky ways of getting your money out, such as depositing into a Chinese citizen's account.
This is why I love the PayPal route: No need to get an official tax receipt. Once you're verified both PayPal accounts, you're completely outside the Chinese system. You can send, from my understanding, nearly unlimited amounts.
"2.1 Sending Limits. We may, at our discretion, impose limits on the amount of payments you can send through the PayPal Services. You can view your sending limit, if any, by logging into your Account and clicking on the View Limits link on the Account Overview page. If you have a Verified Account, we may increase your sending limits."
As it stands right now, I have no sending limits from China to the U.S. I typically send between $500 and $600 a month back home, but I've been able to send upwards of $800 as well without any problems.
So, again... I personally recommend the PayPal route, if only because you're outside the Chinese banking system and don't have to deal with the headaches of getting Tax Certificates and going to the bank.
I think the reason why there's no transfer limit is that I send the money from my Chinese PayPal to my U.S PayPal is in USD not RMB. When I send money, PayPal takes RMB from my Chinese account, converts it to USD and then sends it to my U.S PayPal account. When sending money, you have the option of about 15 different currencies to select from.