Hi,
I picked up a pair of Black Diamond Switchback poles from Anaconda (Mountain Design have them as well) after they topped the list of poles reviewed in Choice magazine. The pair cost me $125.
I'm doing the track in June/July and have heard MANY opinions about one pole or two. I've bought two, training with two, and taking two over.. better to be safe than sorry ! If it turns out I really only need one, then I'll give the other one away or leave it strapped to my pack..