Didn't some dealer have these for $175 a coupe of months ago? I bought one of these Williams plastic GG1's (PennCentral) new 5 - 6 years ago for $270 and thought that I was getting a bargain - and I was, at the time. And, I had to fix it right out of the box! (Broken solder joint on one of the pickup wires; no big deal, and a nice loco, but I though Wms was "perfect"...).
I've seen brass Weaver GG1's go for less than $699.