20oz are more expensive per volume because they sell faster. There’s less of a demand for larger sizes typically go flat too fast for people unless they’re having a party or something, and even in that case they don’t have the convenience of being able to drink from the bottle.
Do you leave your soda uncapped or something? I buy almost exclusively 2 liter bottles and they very rarely go flat on me. I’ll drink one over the course of about 4 days.
No. I never had any issues with larger soda bottles. I would usually buy the 1 or 1.5 liter bottles because they were usually the best deal.
I did some sales work for one of the local soda distributors, and it was crazy how much better the 20oz bottles did in comparison to everything else.
It was the same with energy drinks. Most people would buy single cans for $3 when they could get a 4 pack for $10 or a 12 pack for $20.
We would usually just open the 12 packs at our accounts because the singles simply sold better.