Having previously worked for a large corporation, I found that the costs are always limited to the ticketed price. There are others including employees to run and manage the system; process change; new audits; infrastructure; politics; expertise; training; software limitations leading to longer execution time.
Sometimes saving money leads to spending more money and creating more headaches. Not always, but you do need to understand the nature of the environment you are dealing with.
In our particular case we had a lab where we believed we would be doing good for the company with the $200/month network connection vs the $1000/month connection. Boy were we wrong. The $1000/month connection would have saved so much trouble with internal resources, even if the $200/month connection would have worked just as well.