I honestly don't know of any sites that off discounted Disney tickets, that are legitimate. The tickets this year are 100% non-transferrable. You have to go through a biometrics system before you can enter and this is coded in your ticket so that no one else use it.
If you go on ebay you will see a lot people trying to sell leftover days on their tickets, which cannot be done with the tickets for this year. So you should be very careful.
I don't know if you have looked at prices for Disney tickets this year, but they are more affordable than they ever have been. I always buy through Disney (using my travel agent) to make sure that I am get real, legitimate tickets to be on the safe side. I would hate to buy tickets, go to the parks and find out that they were no good and cannot be used. So I not only would be out the money I spent on the ticket all ready, I would have to pay a higher price than what I could have gotten through Disney if I got them before I left.
Again, sorry I don't know of any websites, which I could be of more assistants.
If you need help getting tickets I would use this link: http://www.mousetrips.com/FAQ4.html This is the travel agency I use and they have a little write up on the tickets that I found pretty helpful the first time I built a Magic Your Way Ticket.
Hope this helps. Have a great trip!