does the roof top cost more money.

5 dollars more

Yes. But not too much.

Roof top is 5 bux more. Ferris wheel and a few slides outside. It's kinda cool but won't be missing much if you don't go. Also elevator quick access to the 10 story slide or climb up through the caves for free.....No view of the arch.

Yes, $5

We went on a Friday night and it was an extra $5 per person for rooftop access. It cost ~ $38.00 total for two people for access to the Museum AND rooftop.

The rooftop is around 12 dollars and the inside is around 7 dollars.