You can get a windows VPS for 30$ with 1 gig memory that will perform quite well. Ofcourse Linux is cheaper but a licence to Windows Web Server edtion is 15$ a month on most hosting companies. You also have the BizSpark and WebSpark programs where you get it for free (for 3 years). Dont think the hosting cost is going to matter much in most cases.
SQL server is expensive but who says you have to use it...
