Well, if you have cash and feel it's worth it, I'd say go for it as long as you're sure it's the best deal on what you want.
Personally if I wanted a Mac and 1 TB of storage I'd buy this and then get an external HD.
The Apple Store (U.S.) - Refurbished Mac Pro Quad 3.0GHz Intel Xeon
It's about as good as what you've got there, has more RAM, and costs tons less. The only thing you seem to lose there is the HD space, which you can easily get back for about $350.
Amazon.com: Western Digital 1 TB MyBook Premium External Hard Drive 1394A/USB 2.0: Electronics
Well, you're about $1350 below, but no monitor, right? But now you can get this.
The Apple Store (U.S.) - Refurbished Apple Cinema HD Display (30-inch flat panel w/ aluminum enclosure)
So now you're about $150 over, but you didn't have to buy more RAM, you have 250 GB more space, and your monitor is hueg liek xbox.
That's a pretty hot package, unless you avoid refurbs like the plague. I know some people do, but they've never done me wrong...