You are absolutely right about this. When my wife and I lived in the Yucatan we discovered that electricity in Mexico isn't cheap. It's actually pretty expensive.

Typically expats ignored the cost and lived a "first world" existence. Most if them had electricity bills running about $400 a month or more.

We were considered "strange" because we lived more like locals. We didn't AC more than one or two rooms in the house. We had energy efficient appliances. We turned lights off when not in use. We were careful about energy use.

Our electric bills were typically $150-$200 per month.

When we had some Mexican friends live in the house for a year, their electric bill was about $90 per month.

They just didn't have all of the stuff we take for granted. They didn't use the washer and dryer (cheaper to take it to a laundry), they used AC only in the bedroom and set it to 78F, they watched less TV, they took cool showers instead of using hot water, etc. Like you say, it all adds up.