Buying Unix?

BarefootClown asks: "I'm currently the sysadmin for the University of Oklahoma Aviation Department. (I know the website looks horrible, it's being redesigned right now by somebody with talent.) Our systems here include two Intel-based servers, one running Windows 2000, one running Linux. The webserver is running on the Linux box. We need a new server, as the old one is about to die (I've lost two of the six hard drives, only one of the two processors is working, and it's just old--we got it second-hand). My boss has been very indulgent in letting me put Linux on a few boxes here, including the webserver, and a couple of web-only terminals (weather/flight planning stations), but he's expressed concern that, if I were to leave my job for some reason, having *nix machines would leave the department unsupported, and out of luck if problems were to occur. Our official departmental (one level up) support channel doesn't support Unix (he didn't support Windows 2000 until the end of last year...), though I might be able to talk to Campus support. This is all becoming a concern because I want to replace the dying box with a Sun NetraX1, which (obviously) doesn't even have the option of running Windows. Any suggestions on how I can convince my boss that it's worth doing? The price on that box is fabulous, at just a bit over a thousand (US) dollars out the door. The nearest PC/Linux box from Dell is about $1400. It seems to me that I know enough *nix people on campus who are looking for jobs that he wouldn't have trouble finding support if I were to leave. How do I convince him that Unix isn't that big of a risk?"