As per Wowhead:

The BlizzCon 2017 homepage and event info page has updated with this year’s convention dates: November 3rd and 4th.

• Tickets are $199, limit four per household, and can be purchased through Universe.
• Tickets go on sale 7pm Pacific on April 5th and 10 am Pacific on April 8th.
• The benefit dinner tickets are $750 and go on sale 7pm Pacific on April 12th.
• Ticket information can be edited through July 14th via your Universe account.
• Badge pickup and the Blizzard Shop once again start a day early, 9 am on November 2nd.