It seems the £40 price tag for the infant kit is actually right as it's now appearing properly on the site. This year it does include socks as well as a shirt and shorts, but for £15 more than I paid last year that's a hell of a lot of money for a tiny pair of socks that I don't want!
It's a bit galling as I've been planning on getting my little girl a shirt with her name and age on the back each year as she grows up and then keeping them to do something with when she's a bit older, so I really wanted to keep that going but I'm not paying that much on principle! It's a bit academic as they don't seem to offering the option to personalise them at the moment anyway.