Should-Cost, and Challenging "This Is Our Best Price"

There is a sentence every buyer hears often enough to recognise the weight behind it, delivered with a small note of finality, that this is genuinely the best price the supplier can do. It is meant to close the subject, and most of the time it works, because the alternative seems to be either accepting the number or descending into the kind of haggling that neither side enjoys and that rarely moves much. The line is effective precisely because it leaves you with nowhere obvious to go. Should-cost thinking is what gives you somewhere to go, and it does so without any bluffing at all.

The idea is simpler than the name makes it sound. Rather than arguing about whether a price is high or low, which is just two opinions colliding, you build up a rough picture of what the product or service should cost to produce, and you let that picture do the talking.

Building the number from the ground up

A should-cost model is an estimate of the real cost behind a price, assembled from its parts. For a manufactured component that means the raw material and how much of it the part uses, the labour and machine time to make it, the overhead the factory carries, the logistics to get it to you, and a reasonable margin on top. For a service it means the people, their time, the tools, and the management layer above them. None of this has to be exact. You are not trying to recreate the supplier's accounts to the cent. You are trying to understand the rough shape of the cost well enough to ask a far better question than "can you do better."

That better question is specific. Instead of pushing against the total, you ask which part of the build-up justifies it. When a supplier holds a price firm while your model suggests material is only a third of what they charge, you can ask, calmly and without accusation, what sits in the rest. The conversation moves off the round number they presented with such confidence and onto a structure that can actually be examined.

Why it changes the dynamic

The reason "this is our best price" works so well is that it offers nothing to engage with. It is a wall. A should-cost model turns the wall into a set of doors, because every component is a separate thing that can be discussed on its own terms. Maybe the material assumption is genuinely out of date and the supplier is paying more than you think, which is useful to learn. Maybe the overhead they are carrying really is high, which opens a conversation about volume or process rather than price. Or maybe the build-up simply does not support the number, and now both of you can see that without anyone having to call anyone a liar.

This is also why the approach holds up under pressure. A buyer who has done the work is no longer relying on conviction or bluff, both of which collapse the moment they are tested. They are relying on a structure they can keep returning to, which means the supplier's firmness meets a calm, specific follow-up rather than a flinch. The price stops being a single immovable figure and becomes a sum of parts, and parts are negotiable in a way that totals are not.

Holding it without making it a trial

The point of should-cost is understanding, not interrogation, and it works far better when the supplier feels examined rather than ambushed. The goal is not to prove dishonesty, because most of the time there is none, only the ordinary padding that any seller builds in expecting a buyer to test it. Walking in with a model and a willingness to be corrected is more persuasive than walking in with a model and an accusation. You are inviting the supplier to show you where your estimate is wrong, and a confident supplier with a fair price will often do exactly that, which is its own kind of useful information.

What makes the difference on the day is composure. Building the model is desk work that anyone can do with a little effort. Holding the line in the room, when a supplier you respect tells you flatly that the number is the number, is the harder part, and it is a skill rather than a spreadsheet. It means asking the next specific question instead of retreating to a vague request for a discount, and staying with the structure when the easier path is to accept the wall and move on. Voice2Evolve lets procurement teams practise exactly that, pressing a should-cost argument against a supplier who defends every component, so that the calm second and third question come naturally when the real "best price" lands on the table.