Schneebly, thank God.. sometimes there is such a 'class divide' on MN.. and I don't evenb do class! I too await bags of outgrown clothes from SIL's kids who wear Next etc.. although there have not been many lately.
I also scour Ebay.
As for Boden, even the sale stuff is about a million times out of my price range..
My kids do have new school uniform though.. I suffered at school for wearing scruffy hand me downs.. I can't do that to mine (unless it doesn't look second hand.) And I do sometimes buy several items of kids clothing at once at Primark. (Even though there have been MN threads where people say they have to hide their Primark carrier bags even they ever stoop as low as to buy anything! )
I don't really buy according to the season though.. maybe just because mine aren't babies anymore so they don't outgrow everything at once.