Hi Gemma and welcome to the Disney Parks Moms Panel.
I have made several telephone calls to the
Walt Disney Travel Company here in the UK on 0800 16 90 730 to try to get a definitive answer to your question.
Unfortunately, after speaking to several Cast Members, I have been unable to obtain confirmation of whether the prices currently displayed for purchasing
2017 Walt Disney World Tickets, is fixed.
However, "The Price You Pay" section of the
Booking Terms & Conditions on the Walt Disney Travel Company's website states that "the prices we advertise are correct at the date of publication. We reserve the right to change or correct errors in both advertised and confirmed prices."
Because of this, I would recommend that you purchase your 2017 Walt Disney World Tickets as soon as you are able to, just incase prices do go up at some point.
Wishing you a magical holiday filled with memories which will last a lifetime!
Emma