I'd say that definitely the cost of the more common materials—PET is probably what I would call the “workhorse”—is not comparable to that of a more high-performance material like the ones you'd see for modified atmosphere control. This is an issue that's very cost-sensitive. Obviously, cost is a big factor in the choice of material.
How that plays out, for example, is in the incorporation of recycled content. There are definitely cost differences between virgin material and recycled-content material on the market, which play into decisions about how much recycled content can be incorporated. That's an example of how cost plays out.