I bought my Show Cocker last weekend and he was £800, from a KC Assured Breeder.
Blue is almost 11 weeks old, and has already found his bark. Not only does he bark, but he also warbles, sings, howls, yodels and whines whenever I go out of his line of sight. However, I don't think this will go on forever, I'm hoping it's 'just a puppy thing'.
If you live alone, be aware that your pup will very quickly develop a strong bond with you, and may not be happy when you 'disappear', even for a minute or two to use the bathroom! I'm having this issue with Blue at the moment, if he can't see me, he thinks I'm not there - even if I'm still talking to him!
I have two friends with Working Cockers, and I find them very different to Show Cockers. They are larger, more muscular, and much more energetic. In appearance, to me, they resemble Springer spaniels.
Definitely do your research first and buy from a breeder you trust, paying particular regard to temperament above all else.
Having said that, it's still the best thing I ever did. I can't wait for the next couple of weeks to pass so that we can start going out for walks etc.