Yes, DO IT. The signup bonus is EASY: 30k miles after spending only $1,000 in 3 months. Most people could swing that.
Look at it from an end-result sort of way. A one-way business class flight from the US to Sydney, Australia costs 55,000 points on Qantas. That would cost at least $3,000 out of pocket. There are major points redemption deals to be had on Alaska.