the price isn't the issue at all for me, as I completely agree with your cost breakdown.
** internet rumor alert**
The main con is a supposed inefficiency in the highest 4 gears that rohloff says does not exist. I have read it from multiple places. I have never tried one though, and would be more than happy to try one out, although I know no one who has one.
If that weren't the case, I would buy one in a heartbeat for a geared ride. The simplicity of the one cog one ring setup is enough for me to accept the 1 pound penalty.