Many agents quote one delivered figure with their fee inside it, and argue that what matters is the final number rather than the percentage. That argument is largely right. An agent charging less who negotiates badly costs you more than one charging more who negotiates well, and a buyer who optimises the fee instead of the total is optimising the wrong line.
The difficulty is that a single number cannot be checked. You cannot tell whether the factory price inside it was negotiated down, because you never see it, and there is no counterfactual against which to test the claim that it was. The question is not whether an agent is honest — most are — but whether you would be able to tell.
Our fee is a percentage too, and a percentage of order value carries the same awkward property in any model: it rises with the price. Two things are done about that here. Checks are priced per job so they do not move with what you spend. And you pay the factory directly, so you see the factory's price, can take that price to another factory, and can read our fee as its own line rather than inferring it.
If you are comparing an all-in quote against this one, three answers make them comparable: what the factory charges, what the agent charges, and what freight and storage cost. An agent who can give you all three is comparable to us and may well beat us. One who cannot may still be excellent — but when the price moves next year, you will not be able to see which part moved.