I'm about to start working on something like this. It is going to be a long journey, but I just want to know whether you are going to pay. This won't be a blog CMS, but enterprise CMS.
For Enterprise level CMS? You'd never get the sale. To cheap. If you want to play in the Enterprise field, you need to do some research into pricing. For a good blog/cms platform, sure. I'd pay $30 a month if it had features I needed. But for enterprise, that's a whole different ball game.