My company charges per hour.
Text based articles maybe 1 hour.
Feature heavey may be 3-4 hours a page.
But all depends, obviously the more interactive the higher the budget.
I could show you something we made on the app store if you want? :)
My company charges per day.
We have an internal Digital Design Squad- Nervous Pixel that works with DPS clients to create interactive and dynamic folios.
We have alot of examples on www.maned.com and www.nervouspixel.com
If you are open to a conversation, I love to set up a time to chat.
Despite having everything already designed in RealView, you're most likely looking a full redesign, especially if you are set on dual orientation (to be honest, I encourage most of my clients to go single orientation for both cost and UX reasons).
It's very hard to give any type of quote without seeing assets, but figure you'll be charged a few hundred an hour by an agency. You can also find very talented individuals that will be cheaper, but the turn around time will likely be longer.
A lot also depends on the completety of the build, the number and type of interactive elements and whether or not custom interactive widgets need to be developed.
If you would like to get into more detail feel free to DM me.