Posted By:
robert aHi Justin,
Let me start by saying that I have a lot of love for T206. 
There are cards that are indeed very tough to find, but I think the list should stop after Wagner, Plank, and the four toughest variations (Magie, Doyle, Demmit, and O'Hara)
Compared to the rest of the set, Elberfield W, Dahlen, Smith Boston and Chicago, Kleinow, and some of the other team variations are tough, but in the grand scheme of things there are enough to go around, so don't get carried away with how much you pay. Just wait for the right opportunity.
Elberfield WA in particular has taken off in the last year. I don't think it's hard to find, but it's all relative.
Since we have so many collectors going after this set, the demand is greater.
Rob