The Pac/Cotto tickets will be up for sale to the boxing public on Aug. 17, 10 am Pacific. I'm a member of Toprank.com, and I can get tix 2 days earlier than the general public. It's free to register.
Check this out --> http://www.toprank.com//News/Default.aspx?ID=4da9673f-7bcb-11de-b109-00065bf70691