b&h has them listed...singles or as kits....the 500ws air is about 1175.....a kit with 2 500 air is about 2675.....
the built in reflectors, wireless trigger and mac control along with the size and weight and superfast recycle and still consistent output and color....for that price....very nice...
they also have 250 and 1000...and all versions non air as well....
i will be getting a demo soon, but was wondering if the whole air thing (the mac control part of it) actually works....