An overseas buyer in Foshan asks the same things, in the same order.
Will you take me to a production line, or only to a showroom? Do you have the products my market needs — and the compliance certificates it requires?
Both have answers. But the negotiation always ends on the third question: is the quality behind this price worth paying for, and will it compete where I sell?
That question cannot be settled by comparing quotations.
Why two quotes cannot be compared
The only coordinate a buyer has is the series. Under one series name, wall thickness, whether the profile is thermally broken at all, the glass build-up and the number of hardware sets can all differ — while the quote carries three lines: aluminium, glass, hardware.
Two "same series" quotes commonly differ by around thirty per cent. Where the difference sits is not on the paper.
Foshan has a second way to quote
Not by series — by the purchase cost of every main and auxiliary material on the order.
The method is not rare in Foshan. What is rare is a buyer who asks for it, because most do not know it exists. Not a refusal to ask. Nobody told them the option was there.
A window breaks into six lines:
Aluminium — the ingot price of the day, plus extrusion and coating (powder, anodising or PVDF), multiplied by the metre weight of each profile, window type by window type, profile by profile.
Glass — the day's raw float price, plus processing: cutting, tempering, insulating unit assembly, coating, laminating, argon fill.
Hardware — priced per set. One set for each opening sash; the grade follows the weight of the sash it carries.
Gaskets and structural adhesive — by consumption: metres of gasket and the number of seal lines, and the size of the adhesive joint.
Conversion — labour, processing loss, management, tax, a reasonable profit.
Certification — amortised across the volume the certificate covers, not charged as a one-off fee.
Add the six up and you reach the real ex-works price. Every line has a source, which is the point: the quote stops being a single number and becomes something that can be questioned line by line.
One more thing that makes this practical: many Foshan extruders keep dies for the standard sections of the markets they serve — Australia and New Zealand, North America, the Middle East, South East Asia, Europe. On a section they already hold, there is no tooling charge and no minimum quantity for a new die. A proprietary section is a different discussion: tooling, and a first order large enough to carry it.
It looks complicated. It takes one step.
Every window order passes one gate before production: the drawing. The window is drawn in window software — frame, sash, mullion, glass, hardware, opening type — and only then does it go to the line.
That software already carries the suppliers' material costs: profiles, glass build-ups, hardware sets, gaskets. Each with a supplier's cost, not a salesperson's memory.
So the material cost appears when the drawing is finished. There is no separate costing system to build — the same gate that tells the factory what to cut tells you what the order costs.
Which is why the first step is not the factory
This method is not for everyone. It suits buyers with an ongoing programme, buyers ordering in volume, general contractors, and window manufacturers. On a small order, an urgent one, or one spread across many SKUs at low volume each, a series price is simpler.
If you are one of those four, the order reverses.
Go upstream first. The extruder and the coater, the glass processor, the hardware supplier, the gasket and adhesive supplier. Ask what those materials cost on the day you buy, and write the numbers down.
Then find the converter. A factory that only assembles: it does not extrude, does not coat, does not make glass. Its margin is in the assembly, so its price is comparable with the next converter's.
Then make a sample, test it, and put certification into the cost — before production is scheduled.
What comes out of that is a genuine factory price. Foshan is not short of factories that only assemble. It is short of buyers who fix the bill of materials and the material baseline, and hold them.
And it has to be a relationship, not a run of one-off orders: the same bill of materials, the same material baseline, the same pricing basis, order after order. Re-quoting every order means nothing was ever locked.
The difference, in one line
Quote by series, and the only question you can ask is "can you do better". Quote by material, and you can ask what each line is for.
The first buys a promise. The second buys a number that can be checked.