I buy rotisserie chickens at warehouse stores. As the article indicates, they're actually less expensive there per pound than raw chickens (using Costco as an example). But the article fails to mention other benefits that have value.
The raw chicken has to be cooked, which requires energy (gas or electric). So does the washing of the cooking equipment.
The cooked chicken saves time in preparation and cleanup, and time has value. The time it takes me to prepare a chicken is worth so much more than the cost of the chicken it's laughable.
The purchaser knows that the cooked chicken will turn out properly, because it has. This cannot be guaranteed for raw chicken. A ruined chicken is a 100% waste of time and money.