Hi pun_lavor,
Are you saying the average sheets per hour rates you're using include ink mixing and makeready? That would put your estimating even more off track than I had realized. The reason is simple: Ink mixing and makeready are quantity independent. They take the same amount of time whether you're running 100 sheets or 10,000.
You may want to download the free edition of Morning Flight just to get a closer look at what's happening under the hood. Drill down anywhere on the screen when the cursor turns into a camera.
Hal Heindel
www.morningflight.com