Hey Steve, I know how you feel. I am just now assembling a simple SAN system for three FC-connected workstations and two more Gigabit-connected laptops, all connected to an XRAID.
The cost is significant, but there's just not many options for high-speed group networking yet. 10 Gigabit ethernet isn't cost-effective yet, so we have fibre channel, which requires expensive hardware.
I balked at XSAN because it required a dedicated backup metadata controller (another Xserve), and cost $1k/seat regardless. I ended up choosing MetaSAN from Tiger Technology, because they have floating metadata masters (every box can pick it up, so no dedicated one) and cost less. It's still $1k/seat for Fibre channel, but only $250 each for Gigabit clients like the laptops, which is fine for SD.
There's a good review
here. I'm still working out a few kinks, and there's a steep learning curve for editors, but it looks like it's all going to work out.
