The worst example I found was in clothing.

I was looking for a plain white t-shirt and walked into Forever-21. (I was having real problems finding a plain white t-shirt).

Men's section had some for about $5, but I have a short torso and they would have been a mini-dress on me.

Women's section had some for about $10, but I have a short...

...slow dawning realization.

It was the same unisex shirt. Being shelved in two places with different prices.

I have never set foot in Forever-21 since. Not that they often have stuff I want, but yes, eternal boycott for such obvious pink taxing.