Of all the decisions in the marketing mix, price has the most direct line to profit: a price increase that holds volume flows straight to the bottom line in a way an equivalent cost cut rarely matches, which is why Marn and Rosiello (1992) call pricing the most powerful, and most neglected, lever available to a management team. Despite that leverage, price is routinely set by whichever logic is easiest to defend in the room rather than the one that fits the situation. Three logics recur. Cost-plus pricing starts from unit cost and adds a margin, and feels objective because every number on the page is an internal fact. Competitive pricing starts from what named rivals charge and sets price relative to them. Value-based pricing starts from what the target customer would actually pay for the value they perceive, established through research rather than assumption (Nagle and Holden, 1995).

The trap is treating cost-plus as the default because it feels safest, when it answers only "what price protects our margin?", never "what would customers actually pay?" or "where do we sit against named rivals?". Nagle and Holden (1995) argue that cost-plus pricing gets the causal order backwards: cost should inform whether a product is worth making at a price the market will bear, not dictate the price itself. For Birchwater, a quick cost-plus calculation is a useful sanity check — the minimum price that protects margin — but, taken alone, it would commit the brand to a price with no connection to what its target segment is actually willing to pay, which the next two lessons set out to measure properly.

Value-based pricing sets price according to the value a customer perceives in the offer, not the cost of producing it or the price a rival happens to charge (Nagle and Holden, 1995). Doing it properly means treating "perceived value" as something to measure, not guess. Monroe (2003) and Dodds, Monroe and Grewal (1991) show that perceived value is shaped by more than the product itself — price itself acts as a quality signal, and brand and store cues shift how much a buyer thinks an offer is worth — which is exactly why a structured willingness-to-pay study, rather than a manager's intuition, is the right instrument for finding a defensible number.

Birchwater already has that evidence. The willingness-to-pay research from Module 2 found that the health-conscious-professional segment over-indexes on willingness to pay a premium and under-indexes on price sensitivity, relative to the other two segments it researched. That finding, not a cost markup, is what lets Birchwater set its price at £1.80 per 330ml: a figure Birchwater sets at the premium end of the category because the research shows its target segment is the least price-driven in the market, rather than in Birchwater's own cost base or a rival's shelf price.

Price elasticity of demand describes how much the quantity demanded changes in response to a price change — a concept Marshall (1890) first formalised by defining elasticity of demand as great or small according to how much the amount demanded changes for a given rise or fall in price. Demand is elastic when a small price rise costs many buyers; it is inelastic when a similar rise costs few. The practical implication for a premium strategy is direct: charging more than a cost-plus or competitive price is far easier to sustain when the demand it faces is relatively inelastic in that range, because an elastic segment will simply buy less, or buy elsewhere, the moment price rises.

Whether demand is elastic or inelastic is an empirical question for the specific product, segment and price range in view, not something to assume from a brand's positioning. The more reliable test is small-scale: compare demand at two or more nearby price points before committing to a number across the whole market, rather than relying on survey intentions alone. For Birchwater, that means testing demand at prices either side of its intended £1.80, among the health-conscious-professional segment specifically, since elasticity for that one segment, not the whole flavoured-water market, is what matters for the price it is actually about to set.

A defensible price recommendation combines all three logics rather than picking one. Competitive position, from Module 4, tells you where rivals sit: AquaVolt's cost-driven scale lets it sell at £1.20 per 330ml, a price Birchwater cannot match without abandoning the focus strategy it has already chosen. Willingness-to-pay research tells you what your own target segment will actually pay. Elasticity tells you whether a price above the competitive anchor will hold, or simply drive the segment away.

Birchwater's small-scale elasticity check, run at £1.70 and £1.90 around its intended £1.80, finds that demand among the health-conscious-professional segment barely moves across that range — direct evidence that £1.80 sits within the segment's inelastic zone rather than past it. That is what turns £1.80 from a number into a recommendation a board can test and accept: it sits above AquaVolt's competitive anchor, it is grounded in willingness-to-pay evidence rather than guesswork, and the elasticity check shows the segment does not punish it. A cost-plus calculation alone, by contrast, would have suggested a price nearer £1.40 — defensible on margin grounds, but one the research shows would leave money on the table.