What Onket means is they aren't on general sale.
That link is the only place you can get them today.
So IF someone bought the £200 tickets today they'd have to be stupid, because there's a link there waiting for anyone searching Ebay for tickets.
E2A: What do usually sell out on pre-sale are the standing tickets. Which is a right pain in the arse because tomorrow I could probably stomach going to the box office and parting with £32.50 but the additional £5.50 booking fee and the £3.50 to send them to me (even by email) is as ever the bit I have trouble with.