I don't see what the anecdote about the other person has to do with your story. It seems like you're citing it to try to imply that Linux can be expensive, but that's not really a valid point based on that anecdote. Their software costs were $0/mo of that $3000/mo. Linux has nothing to do with whatever reasons they had for such expensive server costs. There is no question that whatever their server costs, they would…
Linux has nothing to do with whatever reasons they had for such expensive server costs. It might do. The point is that Node/Ruby etc aren't particularly efficient compared to C# and the CLR, so you need more Server power for a given application. For example StackOverflow ran from a single windows server in the early days, they didn't add a second one till Oct 2008 http://blog.stackoverflow.com/2008/10/adde-a-second-s…
http://www.techempower.com/benchmarks/#section=data-r5&f=ug-...
Edit: FWIW it doesn't test Microsoft SQL Server. Still, for most simple-ish web applications I can't imagine MSSQL server being significantly faster than Postgres or MySQL. Its selling point is really its feature set as opposed to its performance anyway.