I agree, the user can be attributed to a lot of costs, however there are other issues, such as networking, which we were never - even with the help of an Apple engineer - able to solve. That was couple hours I spend on the phone, just trying to see the networked computers.
Add $19 next-day on side support from Dell, and suddenly the mac seems like an over-priced, unreliable, and ill supported computer.
Maybe if the office had virus/spyware issues, I would be singing a different tune, but when my biggest worry in the past year has been dealing with an off-site email server that didn't always want to accept imap connections, Windows just seems to make more sense.
Like I said though, YMMV. Also, Apple would benefit from setting up a dedicated SMB/Enterprise area.