I spent several months looking for a decent model 18 that someone was willing to sell and ended up with a unfired 18-4. Little newer then I wanted but the price was reasonable and I will agree with others here when I say that they just don't pop up for sale as often as other models, they are in demand and don't go up for sale much locally.

I'd probably buy an older one if in nice shape and the price was right if I ran across it.