I got my Chinese visas today through London Chinese Visa Service Centre for £65.25. There are agents/ Tours who will charge you extra fee but it is easy to do it directly. (One agent quoted me £99).
You can also do it through post and pay extra for postage, or you can apply at the centre.
If you apply at the centre then you have to book online appointment and drop the form / passport and collect it after 4 days for regular service.
It took me 15 mins to drop and 25 mins to pick up (I was there at lunch time). There is Visas centre in London and Manchester.
I am now looking forward to my first visit to Beijing. I wanted to see the great wall of China since long time :)