By correctly stating all of your PCB requirements from the beginning, you can be confident that you will receive an accurate quote with a satisfied delivery schedule. To make a sound purchasing decision, you need to be confident that quote is based on the exact same set of requirements. In simple words, don’t risk quotes being open to interpretation.
Incomplete information about your circuit board leaves the door open for interpretation, which can create some unexpected discrepancies regarding how to deal with unexpressed PCB requirements. How does this generate pricing differences between PCB manufacturers?
This happens because all PCB suppliers have different capabilities and preferences, so they sometimes make very different assumptions in order to “fill in the blanks” regarding any information that has not been made clear in your documentation.
Printed circuit board manufacturers often will not ask for clarification ahead of pricing for fear that delaying a quote will cause them to miss the deadline for submitting their bid. Other companies will intentionally offer you a lowball price based on all of the least expensive options, hoping to lock you into a sale first, only to increase your prices later. This puts honest companies who take the time to ask questions in order to achieve the most accurate quote at a competitive disadvantage.
Even when every company behaves ethically, the difference in assumptions between PCB suppliers can affect the quoted price to the extent that it appears each supplier quoted a different circuit board part! This is especially true when the assumptions involve either the laminate material or the surface finish, as both are significant cost drivers.