A quick ‘before we get things started’ note: the figures that I discuss, such as average ticket price, come from official Atlanta Hawks pocket/media guides (media guides prior to 2010-11 can be found here) and these revealed (under the ‘Philips Arena’ section) what the average ticket price for each area in the arena, as such, was.
Example from the 2013-14 season Hawks media guide (the Hawks removed this information in their media guides from the 2015-16 season onwards):
On November 1st 2016, the Atlanta Hawks and the city of Atlanta announced plans to renovate Philips Arena which are expected to cost $192.5 million, with the city of Atlanta pledging $142.5 million while the Hawks would come up with the remaining $50 million.
— Atlanta Hawks (@ATLHawks) November 1, 2016
As you can see, the Hawks have grand plans to make Philips Arena the place to be on an almost nightly basis and, if the team is any good, the arena will really draw the people in. You also have the likes of Sir Foster, who provides a one of a kind experience, as well as the Hawks’ legendary 3D court projections and these, in addition to all the other factors, may lead to more people wanting to become season ticket holders, thus increasing demand. And, as we know, when the demand for something is high it drives the price up and the Hawks are, perhaps, trying to get an early start on this process by raising ticket prices for next season.