The one-server, one-client Basic package is $379; the Network version (up to 25 clients) is $599; and the Enterprise version (up to 150 clients) is $2499. That’s more Macs than I’ve seen in one organization for a long time.
Here at last is a product where Windows doesn’t get to play: BRU Server from Tolis is for Mac OSX and Linux, but not for any flavor of Windows. The Mac version has been redesigned to work the way Mac users think.
For standalone Macs (and their owners), there’s BRU LE, though at $129 it’s on the pricey side. There’s a free trial download, however, so you Mac users can decide for yourselves whether it’s worth it.