Just some quick numbers - in 1 week flat I've been able to create a working prototype for our start-up with the stack mentioned, coding in my spare time (after work and on the weekend). If you know your stuff you can get up and running in no time :)
Our start-up (collectifly.com) is built exclusively on the .NET stack, with ASP.NET MVC as frontend and using a bunch of open source libraries like Twitter Bootstrap, jQuery, KnockoutJS and a few more. For the backend I'm currently experimenting with RavenDB not because I don't like SQL Server but because we're building a social graph, so a NOSQL database seems to fit better.
Have you considered hosting on AppHarbor. Deployment as easy and fast, we can scale and we have a great hosted RavenDB add-on: https://appharbor.com/addons/ravenhq