Under ease of use, I've had at least triple the problems with developers and users on MS servers as I've ever had with linux.
What MS seems to ignore are things like syslog, logwatch, clamd, tripwire, and a miriad of other apps that help maintain security and data integrity. $1,500 doesn't even begin to cover the utility's cost in MS expenses for the apps needed maintain what I consider to be a stable, secure server. In many cases MS just doesn't have the functionality, which seems crazy considering renewing licensing fees (which seems to be completely ignored by MS's lit).
New admins are surprised when they are emailed that users attempt to access / change files they don't have permissions to, or when databases, tables, partitions grow to prohibitive sizes or fill up. Correct setup removes a lot of the guess work and tedium from admin'ing large systems. As long as a competent admin is setting up those servers, I'll take linux every time. The admins may cost more, but guess what? Their work is worth several multiples what MCSE's get paid to do on similar MS systems.
Note: I wouldn't bother to post this, but I've received dozens of "Wow!" and "Thanks for the Linux server, transactions are 4 times faster!" messages from MS admins from dozens of clients whose ass has been saved by well setup Linux servers. And none of those linux clients has failed to ask for a linux equivalent when installing additional servers. That says something.