I agree with cbienlein
There are a few factors here that need to be looked at.
Do you have end user devices who support AC?
Have you provided the infrastructure (BW) to take advantage of a higher speed? Lets face it most users are trying to get to the internet not the internal LAN. If we provide higher speeds do you have the internet BW to support the surfing?
What I think your going to see the market do is buy some first generation ap's to support AC and only use them in high BW intensive areas (unless this is a greenfield where there wouldn't be a reason to buy older technology). Then as more clients have AC capable devices N ap's will be replaced with newer AC ap's. To the few customers who have express interest in AC this seems to be the most cost effective approach.
802.11n (5ghz) as great of a leap forward as it is from legacy (a/b/g) users are still 75-80% on the 2.4ghz band. If they knew what a difference 5Ghz could be there would be very few people still on 2.4Ghz.