This place is great! Given the size of the complex the amount of reptiles it houses is amazing! It is very well organized with a lot of information on the creatures. We took our little ones to Reptilia and everyone had a blast! There are shows every hour, there are feeding times that you can go an watch the handlers feed the reptiles, this place can keep you quite entertained for 1-2 hours!
The $15 is a fair place given the amount of employee, reptiles and I can only imagine the heating costs! Yes, you can probably walk through Reptilia in 30 mins but you are probably not looking at each of the different reptiles and reading up on their info.
Another pro, the Amazon washroom is definitely designed with kids in mind, loved it!