In reply to Y Gribin:
Extremely easy. Bus up from the train station very frequent then loads more between the various towns. In fact it makes more sense for there in particular as you cant take cars into Saas Fee proper for the lifts. Can drive directly to Saas Grund lifts though the bus stops 100m away. However a hire car will give you more flexibility for weather etc! Also there is a bit of a road up to the start of the trek to the hut for the great (SE?) ridge of Weissmies, although probably a nice walk there too. Have been in Saas valley twice, once with a car and once without and there was no real difference tbh. The buses around the towns are free too if you stay in the valley
Post edited at 18:53