working for one of the outsourcing firms ....
... hence an Anonymous Coward.
I've never bought in to the whole 'outsourcing saves cost' thing.
As previous comments have pointed out: You lose in-house experience and expertise; Once they have your crown jewels in the palm of their hand, the outsourcer can then charge exorbitant 'incremental revenue' for any additions or changes; They'll usually shift your support to a 'low wage' economy and use junior staff who will jump ship for more money as soon as they half-know what they're doing; It shouldn't be all about cost saving - there's a reason why the phrase "cheap and nasty" exists.
But on top of that, if you run a service in-house, and it costs £x, you don't have to make a profit on that. You can run it as a cost centre. If you outsource, the outsourcer is in the business of turning a profit - unfortunately, often more than being in the business of outsourcing. How do you expect someone else to run the same service to the same standards to the same support model for less money, and make a profit on it?