Same, my family probably goes through 10 to 15 avocados per week, so we buy them every few days at Costco to have a rotating stock. They take about 5 days to ripen, and then once it feels a little soft, we put it in the fridge, and then they last for a while in the fridge (at least a week).
The one rule at Costco, however, is to not buy avocados from Peru. For whatever reason, the loss ratio is way too high for those specifically.