# SphereFlow V4 — working cost plan

These are planning ranges as of 19 August 2026, not supplier quotes. The custom
borosilicate core is the main uncertainty. Freight, VAT, duty, payment fees,
inspection, breakage, rejects and retail packaging can move the landed cost.

| Phase | Quantity | Expected landed cost each | Cash required |
|---|---:|---:|---:|
| Appearance/fit dummy | 1 | €15–€35 | €15–€35 |
| Functional engineering sample | 1 | €70–€130 | €70–€130 |
| Five revised samples | 5 | €45–€75 | €225–€375 |
| Market-test batch | 50 | €23–€36 | €1,150–€1,800 |
| Market-test batch | 100 | €19–€30 | €1,900–€3,000 |
| Bridge batch | 500 | €13–€22 | €6,500–€11,000 |

## Estimated 100-unit landed build

| Cost item | Per unit |
|---|---:|
| Custom borosilicate core + bowl/downstem | €9–€15 |
| Black PA12 printed shell pair | €5–€8 |
| Cushion inserts and hidden fasteners | €0.50–€1.20 |
| Packaging and assembly/QC | €1.50–€2.80 |
| Freight, duty, breakage and contingency | €3–€6 |
| **Planning total** | **€19–€30** |

At a €69 VAT-inclusive retail price, a €24 landed unit leaves €45 before VAT,
payment fees, fulfilment, returns, compliance, marketing and overhead. Treat
€59–€79 as the price-testing band, not a promised launch price.

## Cheapest responsible path

1. Make one cold appearance/fit print to verify size and grip.
2. Order one functional borosilicate sample and one SLS/MJF PA12 shell.
3. Test splash, heat, draw resistance, cleaning, tip stability and glass fit.
4. Revise the shell only; preserve the glass datum unless tests require change.
5. Get written quotes for 5, 50 and 100 units before taking non-refundable sales.
6. Use a waitlist or clearly refundable reservation to prove demand first.

Do not use PLA, resin or ordinary FDM material as the bowl, chamber, downstem or
mouth airway. A cheap FDM shell is suitable only for cold fit/display unless its
thermal separation is physically validated.

## Current market references

- JLC3DP offers SLS nylon and other plastics through an upload-to-quote service:
  https://jlc3dp.com/
- Current Alibaba borosilicate listings show the wide spread between commodity
  tubing and custom work:
  https://www.alibaba.com/showroom/borosilicate-glass-smoking-tubes.html
- A current Made-in-China 5-piece borosilicate listing is US$9.80–11.80 each,
  but the V4 custom core should be expected to cost more at sample quantity:
  https://shunyiglass.en.made-in-china.com/product/pJUYNFoMEukZ/China-OEM-ODM-Classical-Heart-Glass-Hookah-Smoking-Pipe.html

