Not sure where you're seeing the $3 avocados. Even in SV, it's like $1 per unless things have changed in the last several weeks.
This aligns with my recent shopping experience.
https://www.nytimes.com/2017/08/28/business/amazon-whole-foo...
if you want to talk about vegetable affordability, lets start with lettuce, carrots, and broccoli.
But you probably want to use them that day which I see as a feature.