It costs $37 if you are at the Fortitude Valley McWhirters Secure Parking lot for 3+ hours, there is however a validation machine at a convenience store, that will reduce the price to $8 for the whole day. This is a lot better than the 9AM early bird offer, which charges you the full fee, if you leave too early.
The validation machine is at the Ezy Shop convenience store, which is roughly at 105 Wickham Street, Fortitude Valley.
What the store looks like: http://upload.ozbargain.com/2012/07/23/8995_street_view.png
Note that this is for McWhirters, not to be confused with Valley Metro which is only about 100 metres away. How old is that sign …. the maximun day date was only $18? and now it's $37. Ahhhh, seems like it was only yesterday that it was $18 … probably was! But what's the deal for the validation? Just buy anything of any value?