A few years ago I was traveling to San Diego rather frequently, at least 3 times a year, sometimes 4 and had decided I would benefit from a membership. Unfortunately, a couple of months before making this decision, the zoo changed their membership policy to be that if you live within a zip code range, you could get a membership for X amount, but if you live outside of that range, the price was almost double. I don't know of any other zoos that have this policy and it upset a lot of regular visitors who lived outside the zip code range and they complained about it. A lot.
Well, I really wanted a membership and I didn't think I should have to pay double the amount so I bought a membership and gave my address as the hotel I stay at. When I made my first trip to San Diego after doing this, I went to the membership booth and told them I'd recently moved to San Diego and had bought a membership, but I was having trouble with my roommate, saying I wasn't getting my mail. The gal had no problem with changing my address to an Arizona one to ensure I got my membership stuff and they never asked for proof of a San Diego address. I had that membership for four years and they just kept sending everything to my address in Arizona.
Yes, this was dishonest and no, I'm not proud of what I did, but I literally missed the chance to do it the right way by a couple of months. Eventually I stopped renewing it because I was no longer going as often and they STILL send me membership offers every few months.
I have no problem with a zoo offering a small discount to locals, but to charge twice as much is ridiculous.