You said "There's a point of diminishing returns with cost per roll decisions. Four dollars vs. one? Sure. One dollar vs. a quarter? Not so much." I'm not so sure what this means. I assume you're talking about replenishing etc. Bottom line, does your phrase "four dollars vs. one? Sure" mean you can pretty easily develop for $1 per roll? But that getting it down to $0.25 per roll is more difficult, if not impossible?
If so, sounds good to me: $1 per roll is awesome and I would not even think of working really hard to reduce that by a few quarters, with the added risk of uneven development.