Send me a private message if your interested. Will give you more details about it

I doubt you're going to get any takers here when better tickets are still available, as far as I know, and anyone on here who wanted tickets this early is likely to be clued-up enough to have bought them when they first came out.

Your best bet is probably to try to sell them on a site like seatwave http://www.seatwave.com/search-tickets/search/v2?w1=atp+world+tour+finals or viagogo http://www.viagogo.co.uk/Sports-Tickets/Tennis/Barclays-ATP-World-Tour-Finals-Tickets, which for this event (unlike Wimbledon) is legal.

They may not go immediately unless they have already sold out, but being semi-final tickets they might have already sold out and, if not, I'd guess they will go nearer the time if you price them sensibly - most likely 1-3 weeks before the event when people are looking for tickets but before the supply on those sites jumps when people find out just a few days before that they can't go.

Hope that helps.