i was going to buy that one ... ^^
if posting amazon links isnt allowed im sry
Not necessarily 40, i was saying that due to prices. for instance i got these:
http://www.amazon.co.uk/dp/B010SDQXPY (10quid minidp adaptor to multi output)
http://www.amazon.co.uk/dp/B00LLUEJCS (23 quid, usb3 to ethernet and hub)
which both work with my sp4 and using both i can replicate the Dock (which would save you 42quid which can be used for other things) but it's different and not quite as fitted or an elegant as the dock attachment :-) dock might actually do more (i haven't looked into its details but i'm under the impression the above 2 do the same thing..does the dock also provide a power input or something?)