what does it cost

I went there with a city pass . Basically $70+ to make one and you can get a lot of attractions for free after you give that to the venues.

City pass is great lots of attractions see the under city tour.

As of May 14, 2018, at the door prices: 1) Space Needle General: $26 Youth (5-12): $17 Senior (65+): $22 King County: $21 2) Space Needle + Chihuly Garden General: $42 Youth: $26 Senior: $37 3) Seattle Center 4-pack Adult: $59 Youth: $39

I Bought tickets online in advance. Saved $10 a ticket. Some had groupon. Search Seattle.