When I first looked into CD last October, I emailed 4 local CDC's to find out prices and information. They all stated £1.80 for each shake or soup. I couldn't afford it, so I haven't been unable to commit mystelf. Now that I can afford it, but money is still very tight (as I am studying full time) I emailed more local CDC's to try and get them a little cheaper. I will be getting the shakes and soups at £1.70 each. 10p doesn't sound like much, but it soon adds up. But remember, the only reason for trying to get them cheaper is because of my money situation at the moment.
Personally I feel that the service provided by the CDC is the main thing to focus on. Regardless of price, the right help and support is vital to the success of each individual. Obviously it will differ from one CDC to the next, but if service improved with price, it would be wise to spend more, because in the long run you will benefit from that.
I'm only talking about theory here, as hopefully all CDC's offer the necessary support to help anyone succeed, but like any service offered, there are always differences.
As my CDC is saving me money on the supplies, I intend to pay her that money as a bonus at the end if she does a good enough job of helping me reach my ultimate goal, as I should be working by then.
Just my 2 cents.