They are a WONDERFUL family dog!
We currently have a working springer and a working cocker - first spaniels we've ever had, as prior to this we had always had terriers.
We've never regretted getting the girls. They are sweet-natures, biddable, easy to train and an absolute joy! They're not noisey (this is why we moved away from terriers - they bark almost constantly, though they have lovely personalities) and will only bark if there's something to bark at. They aren't bad chewers - very little has been accidentally destroyed (only a slipper and a couple of socks - the terriers cost us a fortune in damaged furniture, clothing, soft toys, flooring etc).
Their only "fault" if it can be called that, is that they are "mouthy". They pick things up (anything they can't hold of) and bring it to you. This means that if you aren't careful you will find one glove where you left it, and the other where the dog has dropped it! They are also quite bouncy, but easy to train out of it unless they are very over-excited, but a 7 yo should be fine, though they could set a toddler flying. Their mouthiness can extend them taking your arm or hand in their mouths affectionately, but they DON'T bite - I must stress this - they just hold you, their mouths are very soft.
I lightly groom mine three or four times a day because I don't want to have to clip them, but their coats are easy to maintain as long as you don't let them get matted. They dry off very quickly after getting wet or muddy - and they will get wet and muddy.
Of the two, our springer is the most beautiful dog I have ever seen - ever! But she isn't as bright as the cocker by half.
Our pretty little cocker bitch is the most intelligent and easy to train dog we have ever had. She's bright, joyful, loving, full of fun, obedient (mostly
) and just wonderful. If we had room for another dog, I would get another cocker in a heartbeat!
They do need a lot of exercise though, and for all cockers aren't a large dog, they are strong for their size, and I recommend that you train your puppy to heel as soon as you can (puppy classes will also help with socialisation - they aren't troublesome dogs, but all pups need to learn how to behave with other dogs as I'm sure you're aware). S/he'll learn quickly as they are very bright and eager to please.
Also - they eat a huge amount for their size, but you will find they run it off.
£900 isa lot, but TBH it is what you will expect to pay for a well-bred, registered pup whose parents have had all of the appropriate health tests.
I hope you decide to go ahead - you won't regret it. And of course, we will want photographs on here . . . .