Priced per unit with quantity breaks. Vendors quote steps at 1 / 5 / 10 / 25 / 50 / 100 / 250 units, and the per-unit rate drops at each break.
It should not be. Setup is per design and per print run, not per SKU when pieces share a run. Ask to consolidate.
Gang designs onto one sheet and standardize sizes. Most of the cost in short pieces is setup and material waste, not the printing.
The same product family is tracked in 11×8.5, 6×1, 8×9. Quotes are NOT interchangeable across variants, so match the spec before comparing.