The quote was real. The volume wasn't.
You have three quotations on the desk and one is eleven per cent cheaper. Before you act on that number, check that all three are quoting the same thing. In this trade they usually are not, and the gap is almost never in the base oil.
Nobody is lying to you
It is tempting to read a low quotation as a trick. Usually it is not. Every supplier quotes against a set of assumptions, and where your RFQ left an assumption open, each one filled it in differently — and, being human, in the direction that made their number look better.
Which means the fix is not to distrust the quotations. It is to close the gaps in the request so there is nothing left to assume.
The first gap: the volume the price is calculated on
A price per litre is meaningless without the quantity it applies to. A quotation built on a full 20 ft container of one SKU will beat one built on a mixed container of six, and both are honest.
So the question is not what is your price. It is what is your price at the volume I am actually going to order — which, for a first private-label programme, is a mixed container. Ask for the price at that mix, not at the supplier's preferred one.
The second gap: pack size, which is where the cost actually moves
Filling 200 L drums and filling 1 L bottles are different operations with different labour, different packaging cost and different fill losses. A quotation that assumes drums will always beat one that assumes retail packs, and the difference will dwarf whatever you negotiated on the formulation.
If your programme is motorcycle oil in 1 L and 800 mL, a drum-based price tells you nothing at all. State the pack breakdown in the RFQ, by SKU.
The third gap: the Incoterm, and the two words after it
FOB, CFR and CIF are not interchangeable and the difference is not small on a container. Quotations also differ on the named port, which matters more than buyers expect.
Ours are quoted FOB Xiamen as standard, with CFR and CIF available, Incoterms 2020. That is not a better answer than anyone else's — it is simply a stated one. A quotation that does not name the Incoterm and the port has not quoted a landed cost, and a landed cost is the only number you can compare.
Four lines that make quotations comparable
Add these to the RFQ and the eleven per cent usually disappears, or turns out to be real — either way you will know which:
1. The SKU list with the pack size and the quantity per SKU, not a total volume. 2. The Incoterm and the named port. 3. Payment terms in full — ours are 30% deposit with the balance settled before shipment, which is standard for a first order; what matters is that you are comparing like with like. 4. What is included beyond the oil: artwork, plates, cartons, documents, inspection.
That last line catches more money than the other three together.