I would pay a fortune for them if I had tooo, love them, they didn't have them when my older 3 were small and we lost soooo many socks. Devon is 17 mths now , we wore them till 12 mths, (shame they didn't do them beyond 12 mths size as he didn't walk till 15 mths and is still wobley!). We have never lost one sock!!
As for washing , I only ever handwashed them, didn't have to do it often, and dried on kitchen window, didn't take long theres not much too them.. Ebay have loads more exciting colours than the blue, white or pink that's in mothercare...
Did have lots of ladies ask if they were foot supports and what his issue was? but I still loved them
If you use a baby carry, no more grabbing babys feet every two mins to check if socks were still there.
Get some , you won't regret it