Last I knew, Visual Studio Professional was about $500 for a single user. SQL Server can get expensive depending on what you're hosting, but IIS and ASP.NET don't cost anything. All you'd need is a Windows box for those.
SQL Server on RDS includes the SQL Server license and is very cost effective for what you get. (Backups, point in time restore, etc). They also offer EC2 with SQL Server but I’d rather pay the slight premium for the additional management.
