"software costs are a small percentage of an overall IT budget. The largest part of the IT budget is usually staffing, not software."
But if you want to speak of users its not just the tweaking of code you get with opensource. YOU never have to worry about a subscription model for software (which has been floated by various closed source companies like Microsoft and Sun) where one day you need to resubscribe rather than jut outright own the software that you use.
Although an MS proponent, and have been for years, it is at this point that I will begin a serious move away from Windows.
I have no interest in resubscribing my software every year or whatever.