According to a report by Network World, a study performed by them has declared that the average Mac is half as expensive to maintain compared to a comparable PC in a business setting. This conclusion was derived by researching the average costs of technical support needs, third party software developed to fight hackers and viruses as well as spyware and other security oriented software applications.
The report later goes on to address that those costs combined and maintained on a yearly basis leads to a final annual maintenance cost of anywhere between $1300 to $4000 USD. Though not completely scientifically studied, the point made by the report suggests that a lower maintenance cost associated with owning and running a Mac based system in a business setting should be a major selling point for Apple.
News source: Network World