http://www.calgaryzoo.org/Admissions..._admission.htm
$5 may not seem like alot but for a family of 4 it will cost you the following during the summer
2 x 18 = 36.00
2 x 10 = 20.00
parking = 5.00
$61.00 just to get in the door. If you take transit it will cost you even more
2 adults 2 x 2.50 x 2 = 10.00
2 kids 2 x 1.50 x 2 = 6.00
So taking the train will cost you $72.00 just to get in the door. That does not include any drinks/snacks you either buy there or haul on the Train with you.
For some that can be expensive.