Paid £112 (plus postage) for some sale shoes. Then I got the shoes and they have a £95 tag on them! I don't think HoF should be charging more online than in the shops, on principle. It may 'only' be 17 pounds, but I think that's a lot (and that's excluding the £5 postage charge).
No idea how often this may happen on other purchase, and what the price difference may be on those - so I'd just say be wary of buying anything online from HoF...
(Btw I did email HoF customer services a while before posting this, to get an explanation, and heard nothing back at all)