I got similar devices off eBay a while back. The problem was not the devices themselves - they still work. After I got deeper into off-camera-flash, I found that could not expand to multiple tirggers. Not because the devices didn't support this configuration. They were no longer available just when I wanted to buy more.
This is one advantage of Pocket Wizards. They will likely still be around in two years.
BTW: Even knowing this, I still don't own PWs. A bit too pricey for me, all things considered. But also a nice product.