I'm really glad some of my advice has been of help! I know how frustrating Ticketmaster's systems can be, so I like to give any advice I can
A further note on the eBay touts - eBay requires that all event ticket listings give the original face value of the tickets (in this case, £75 or £50). You can report any listing which does not do so by clicking on the 'Report this Item' link at the bottom of the page. You may also be able to kick up a fuss with eBay because selling the tickets for higher than face value is against the terms and conditions set by Ticketmaster. Give 'em Hell!
As far as I know regarding items sold that aren't in-hand, buyers have to have the tickets in-hand within 30 days. As there's no guarantee of this, I think they're on dodgy ground.
I don't really know much about the Ticket Exchange thing, but from what I've heard, it's not exactly a lovely thing

I can't pretend Ticketmaster is anything other than another business looking after its profits, but it is still interested in unsanctioned touting (i.e. touting not taking place on their own website). It's a route worth trying, at least...