I didn't assume anything. I presented a scenario where that's exactly
what happened.




But that' only one of many possible scenarios when changing the page size, and the original post implied that there might well be changes to fonts and margins, which also would affect page counts. It would hardly be automatic that the count is going to grow under such a possibility, and even if it did, under your scenario the savings would be greater than just the paper cost since you save four sets of plates and the setup time required for the changeover. Since most book jobs like this are delivered to the bindery as folded signatures that are trimmed after binding I wouldn't expect the cost to go up, but rather down, since you have two less sigs to deal with.

Peter