My group went here originally just to go to the bar and see the view, however we decided to just purchase tickets for the 360 observation deck. You get one drink included with the price of admission, not too shabby. Tickets are about 25.00. The view of the city is great, there is a gift shop at the top you can buy things and of course a bar. There is no time limit on how long you can stay at the top, which is nice.
We were just going to go to the bar on the 90 something floor to avoid this 25.00 ticket cost, but they told us you have a minimum purchase of two drinks and the drinks are 10.00-12.00 a piece. Basically, the 360 observation ticket balances out and you get more than just a bar. There is an open air area on the observation deck where you can take pictures and get a breath of fresh air.