Please define "expensive". If it's a consumer app, hacking a wordpress template should only cost about ~$500.00 or hacking the sample projects from Parse.com can cost about ~$500.00-$1,000.
If it's a enterprise play, then you should be able to close $50k-$2mil for a paid project engagement from an enterprise client just by having a good powerpoint deck and an awesome sales pitch.
If neither options works, then you probably need to refine the idea more.
Interesting concept. I was actually thinking about building something similar. Now I see just how hard it is. The problem is trying to take a complex system of tools; messaging, wiki, project management, dropbox, integrating it into a simple solution and more powerful solution.
Mobile Apps & Mobile Games are good examples to look at for their onboarding process. You have to win the user in 1.5 minutes.