world CLIMBERS party
Fly to Cagliari with Ryanair.
Cagliari airport is well served for buses.
There is a bus into town from the airport each half hour (xx15 xx45) and it takes 10′ to the bus station in the centre of town.
From there there are buses to Ulassai.
Check times in ARST website.
It's in Italian, so:
FER = Mon to Sat
GIOR = every day.