All costs of a part are summed into the cost price: material, electricity, depreciation, maintenance, misprint buffer, accessories, base parts, packaging, labour and storage. Profit margin and the further markups (discount, cash discount, cashback, platform fee) come only afterwards, once at the top, via the pricing profile. That way every cost component carries margin exactly once.

Some items occur for every part, others once per order. Per unit: print time (every part is printed), material weight and post-processing (every part is deburred). Per order: preparation and slicing (once, regardless of how many parts on the plate) and the shipping handling (one parcel goes out). For multi-unit orders the per-part price therefore drops, because the order costs spread across more parts. Packaging decides per entry: a single bag counts per unit, a bulk box per order.

Depreciation spreads the printer’s purchase value (plus extra cost) over its lifetime in operating hours and allocates it by actual print time. It means the wear of the device through use, not tax-law depreciation on the balance sheet. A part that prints longer carries more device wear.

A base part is its own saved calculation that enters another calculation as a cost item, useful when the same self-made part appears in several products. Its cost price is carried over (not a sell price), so margin is applied once on the end product. A purchased part with a fixed price belongs in accessories instead. When a calculation is saved, the base-part value is frozen; if the base part changes later, the saved calculation stays unchanged.

Scrap and wear are device-specific: a cheap printer has more misprints than a reliable one. Misprint rate and maintenance rate can therefore be set per printer. If nothing is set on the device, the default value from Settings applies as a fallback. Electricity stays global, because it is the same for all devices.

A saved calculation is a snapshot: it records the values actually used and the computed result. When opened, the stored result is shown, not recomputed. So a price you quoted to a customer stays unchanged, even if you later change library values, delete a device, or the formula is adjusted. To reuse an old calculation as a starting point, load it as a template into a new working state.