First of all, I'm glad we could help.
The guys that responded to this post, excluding myself are some of the best around (along with some other guys that will read this post in the following week).
Yes, X10 is cheap, but not always as reliable as you might think. When X10 came out, modern electronics didn't pollute the powerline with noise, and new tools are needed to make X10 work with all those new toys.
Insteon is susceptible to some of the same noise follies as x10 and is more expensive. Z-wave seems to hit a limit when you get about 30 modules weighting down the system. I'm not familiar with UBP, but I'd say there is a limitation there as well.
I've run a system with somewhere just shy of 200 devices on the x10 protocol for many years now and there's no way i could afford to do it with any other technology (I buy 8 units for $50 in package deals, or get stuff from eBay for next to nothing).
When you factor in the price of a repeater, filters and an x10 signal meter, I think I'm still ahead of the price curve versus a good system.