Listen – no one placed a bid on the first auction, so it’s unlikely anyone, other then you, will bid on this auction. Place a proxy bid – it’s very likely you’ll get it for £7.99. Even if you have to do the BIN, it’s only £4.01 more then the original auction’s starting bid. You said that your “maximum bid was well over that”, so you were obviously prepared to pay more for the shoes, and for all I know, that maximum bid of yours may have been over £12.00.
If I was concerned about “my Autistic son”, I would spend less time focusing on £4.01, and more concerned about getting the shoes for him – but that’s me.
I don’t normally get this way, but you sound like you’re more interested in “woe is me-ing” then in solving any specific issue.