Is the application fee too expensive? Am I being cheated?

I have spent 9 months in Beijing, firstly on a 3 month business visa (the "consultancy" type) and then renewed twice whilst in china. I dont have my passport to hand right now but I believe the next 2 visas were of the "student" type (I was working in a language school and they didnt want to declare us as offically doing paid work, so they did this to get around it - I think this is fairly common practice).

Anyway I came back to the UK on 29th November, which was the day my last visa ran out. I have since tried to apply for another business visa in the UK, only to be rejected twice, and told I needed a Z type. Now, the school I have been working at in china said they can obtain a Z type for me by going through an agency in Beijing, but that the cost for it plus agency fees is 15000 rmb!! (about £1500!!) This seems insane to me! why is it so much more expensive this time round? I have this nagging voice in the back of my head that is telling me the language school on Beijing are trying to fleece me out of money? Can anyone clarify if this extortionate amount of money can in any way be deemed reasonable, or am I being conned? Thanks, Harry