1. Sample inputs
| Order quantity | 2 | Material per part | 120g |
|---|---|---|---|
| Filament | 1kg / $20 | Extra material | 5% |
| Print time per part | 8 hours | Average power | 120W |
| Electricity | $0.18/kWh | Machine rate | $0.50/hour |
| Failure rate | 10% | Consumables | $0.50/part |
| Hands-on labor | 20 min/part | Labor rate | $20/hour |
| Order overhead | $1 | Marketplace fee | 6% |
| Cost markup | 30% | Tax allowance | 0% |
2. Direct cost for two parts
120g × 1.05 per part
252g total$0.02/g × 126g × 2
$5.048h × 0.12kW × $0.18 × 2
$0.358h × $0.50 × 2
$8.0020/60h × $20 × 2
$13.33$0.50 × 2 + $1 order cost
$2.003. Add expected reprint cost
Repeatable cost per part is $2.52 material + $0.1728 electricity + $4.00 machine time + $0.50 consumables, or $7.1928. At a 90% success probability, the expected repeatable cost is $7.1928 ÷ 0.9 = $7.992.
($7.992 − $7.1928) × 2 = $1.5984Direct cost plus the failure reserve gives an expected cost of $30.32.
4. Add profit and gross up for the selling fee
The two-part quote is $41.93, or $20.965 per part before any separate shipping or design charge. The per-part number changes with quantity because order overhead is shared.
5. Compare the failure-rate assumption
| Failure rate | Expected cost | Final quote |
|---|---|---|
| 0% | $28.72 | $39.72 |
| 10% | $30.32 | $41.93 |
| 20% | $32.32 | $44.70 |
This comparison is not a reason to accept a high failure rate. Improve the root cause first, then use the remaining observed risk in the quote.
Shipping, CAD changes, special finishing, purchased hardware, liability and market positioning are outside this example. Verify fees and tax rules for your location.