I would go freemium. Make the base app open-source and free (as in freedom, though you could also make it free as in beer, too).

You could do something wonky with your license where it's free or nearly so for noncommercial use and then scale up the licensing costs by some metric for commercial use.

Or you could go the normal freemium model and determine via beta customers what businesses will actually pay for and then charge to do that well. I'd pick this option.

Realistically though, if it's the type of product that only enterprise will ever be interested in, then the discussion is mostly moot.