Magazine app design and creation

I need a cost for the design production and creation of an app similar to these;

http://itunes.apple.com/gb/app/blades-magazine/id482096811?mt=8
http://itunes.apple.com/gb/app/loop-aviation-magazine/id465155026?mt=8
http://itunes.apple.com/gb/app/p1-aviation-magazine/id445485771?mt=8

There is going to be around 100 - 164 pages of editorial and the app needs to be available on all iDevices, Android, Playbook and Kindle Fire platforms.

We would prefer to have a designer that is able to visit one of our offices in the UK but isn't essential.

Thanks,

Happy bidding