I'm not clear what your question is here. If you are suggesting that Tableau consider different pricing models than what it currently has, you might want to vote up and comment at Improved server license model for medium size companies . If you have questions about prices for your organization, I suggest discussing them with your sales rep.
Hi Kishore --
I'm having the same issue. I'm considering passing along the costs like this:
1a. Flat fee per year per company to access the data
1b. Hourly rate for any work I do to create, manipulate and/or administrate the data
2a. Flat fee per year per company to access ONE dashboard. Scalable flat fee per year per company for access to more than one dashboard.
2b. Same as 1b.
Since I'm 5 months behind you on thinking about this, I'd love to hear what you came up with, and if your concept worked financially for you and your business.