I noticed when N&W 611 came back out the number of models for sale jumped on E-Bay, at 25-30% higher than the previous year when I bought mine. I guess sellers were thinking they could make a buck or two on the 611's return to the rails.
If I knew then what I know now I would have started off buying those Williams/Samhongsa brass steamers sooner, I got the 4 I have at good prices IMO, even if they are lacking in the amount of detail. I'd be most happy with owning only those 4 and not the other 6 steamers and 8 diesels I have.