Priced per unit with quantity breaks. Vendors quote steps at 1 / 5 / 10 units, and the per-unit rate drops at each break.
No. Commercial-grade hardware is reusable for years. Buy the frame once and reorder only the printed graphic, which is the cheaper part.
Mechanism grade. An economy unit and a commercial one look alike on paper but the cheap one fails sooner. Pin the hardware grade before comparing.
The same product family is tracked in 12mil stock. Quotes are NOT interchangeable across variants, so match the spec before comparing.