Price: $1.00 USD to top (not sure on extreme package $3.00 USD?)
I thought this was a good idea in Manizales, Colombia. They made an ordinary water tower into money making venture. They charge one dollar to go to the top. Plus they have an extreme package (not sure on price) where you can put on a climbing harness and walk outside the upper deck.
Seems like a good ideal for cash strapped cities.