For optional products and services, I guess that seems somewhat understandable (but I'm not 100% sure), but for mandatory products and services, that doesn't seem right.
I went to an outdoor event a few years back in September and when I tried to go through the gate they said no coolers. I said my cooler (soft sided 6 pack size, not big) only had water and showed them. They said no coolers and no outside refreshments. I went back to my truck, put the cooler inside and pounded a bottle of water on the walk back. A few hours in, I was thirsty and they were charging $8/bottle of water. That was not ethical.
My brother runs a business that does regular service for customers and also emergency service. The rates are based on planned vs. emergency and he is a 24/7 business. The rates are published and he sticks to those rates. After a natural disaster, many of his competitors raised their rates by a factor of 3 or 4, but he didn't. It was at the emergency service rate, but he wasn't price gouging, while the other guys were. That is ethical. Regretfully he has had to raise his rates (with notice) due to fuel prices, but the rate change was based on the change in fuel prices (assumed to be $5/gal, even though it is really $5.50/gal-ish right now, he's absorbing the rest).
Not sure if those are just outliers or if I'm just an idiot, but waiting until someone is about to get a huge EPA fine and then telling them the job is going to cost $30k, not $7,500 seems wrong. Also telling someone they can't bring their own water in to an outdoor event, but then charging $8 for a bottle of water seems fundamentally wrong. Charge $40 for a Coke or beer, but water at an outdoor event when its 98 deg is not optional and $8 for a bottle of water in the US is not logical.
Sandy.