Comparing the quotations of two lighting suppliers is rarely as simple as two numbers. The lowest unit price in bidding often corresponds to the highest total cost, and the gap is often hidden in the few lines omitted from one of the quotations.

A quotation that can be effectively evaluated should state item by item: model and description, power, luminous flux and its based test standards, color temperature and color rendering index, beam angle, IP and IK level, drive brand and model, shell material, warranty period, packaging method and quantity per box, minimum order quantity, delivery time, and price. Any item missing from this list will become a question that the purchaser has to ask; under the pressure of delivery, this kind of question is most easily forgotten.

Business terms also deserve equal attention. Trade terms determine where costs and risks are transferred-EXW leaves everything behind the factory door to the buyer, and DDP puts import tariffs and final delivery on the seller-so a quote that states the price but does not include trade terms cannot be directly compared to a quote that states the terms. The current version is Incoterms 2020, and a quote that still quotes the 2010 version of terms is worth questioning in itself. The payment method, currency, validity period of the quotation, tolerance for excess quantity and shortage, and the handling method of spare parts should also be written on paper.

Finally, look at how the warranty is written. The warranty that only guarantees the drive or requires the buyer to return the entire lamp at his own expense is completely different from the warranty that "provides replacement lamps with labor compensation"-even if both are written as a "five-year warranty."