No one has posted it here, but the concert tickets go on sale May 16th.
It will be 10am for the VIP tickets, and 11am for the GA. Both times are Mexico City times.
There will be a total of 400 VIP tikets available, and they cost $2200 (About $142USD) each.
GA will cost $585(About $38USD each.)
GA tickets will be sold on ticketmaster, and VIP will be sold here:
http://jfest.ws/In order to receive the VIP tickets, you must pick them up no later than the 18th, so be sure to get in on that day instead of the day of the concert.
The place to pick up the tickets is called J'Store.
https://www.facebook.com/JStoreMXIf you can't get there on the 18th, it is suggested you have someone pick it up for you, and you can request a specific person to pick up when you purchase the ticket.
VIP seems to come with Early entry to the front and some kind of meet-and-greet.