Every part, priced where it was read.
A bill of materials is a CSV beside the design. Each line names its maker, its part number, its source and its price, and the roll-up adds them up.
Case study · UpperBody-001
Two arms, two hands and a head: $1,630.83 of parts.
UpperBody-001 is the module of two arms, two hands, a neck and a tablet head that DeskAssistant-001 and Centaur-001 share. Its BOM has 95 lines in six sections. The servos are two thirds of the money.
- lines, every one priced
- 95
- name a source
- 93
- at a quantity of one
- $1,630.83
- at a quantity of 100: no price break was read
- $1,630.83
hardware/modules/UpperBody-001/ee/bom.csv输出 case-studies/sourcing-and-bom/stats.json工具 scripts/sites/case-studies.mjs sourcing-and-bom运行于 This computer (dell-gb10-1)时间 Where the money goes
29 Feetech servos, each price with its page.
A line's source says where its price was read and when, with the other offers seen. The four largest lines, as the file states them:
What is not done yet: only 4 lines carry a date of reading, the qty-100 column repeats the qty-1 price, and EEG-001's five board BOMs (276 lines) list references, values and footprints with no source or price.
- 12 STS3032 hand servos at $32.50, Switch Science, read 2026-10-15 (JPY 4,862)
- $390.00
- 5 STS3250 shoulder servos at $73.99, OpenELab, read 2026-10-15
- $369.95
- 12 STS3215 arm and neck servos at $27.99, OpenELab, read 2026-10-15
- $335.88
- 1 Galaxy Tab A9+ 5G head, Bechtle, read 2026-10-15 (EUR 253.99 net)
- $296.00
hardware/modules/UpperBody-001/ee/bom.csv输出 case-studies/sourcing-and-bom/stats.json工具 scripts/sites/case-studies.mjs sourcing-and-bom时间 Price your design from its own files.
Keep the BOM beside the design, name each source, and an agent can read the offers again when you are ready to order.