Applying for a new visa

Hi, I've got a z type and a Chinese residency permit fo that runs out in August, it was a year long one. How can i renew it without going back to the UK? I'm currently in Guangzhou, so going to Hong Kong could be an option. Do you know roughly how much it should cost? Someone I know recently applied for a 6 month one through the company he works for and it cost him 7000rmb, I can't afford this and it seems very high! Is there a way to directly apply without going through a company? Or extend my residency permit? When i arrived we were told if we wanted to stay longer the easiest thing to do would be apply to extend it....