The electronics are around $150 for the CC-Lite and RS Commander. The basic install isn't all that bad.
There are two sticking points on this installation.
#1. The railings are VERY fragile, I have some broken pieces that I'm going to have to figure out. I have some brass rod coming, and I may just make railings and forget about the flimsy plastic ones. I have no idea if I can get pieces from Williams.
#2. The electrocouplers have to be extensively modified to work in this application as you can see from the first pictures in this thread.