Is a volume discount worth borrowing for?

Suppliers offer volume discounts because they want a bigger order, not because they want you to have cheaper goods. Whether it is worth borrowing to take one is a four-part calculation, and only the first part gets done.

The calculation

Part three: the costs.

• Financing at an illustrative 15 per cent for 4.6 months: 2,898
• Storage at an illustrative 0.9 per cent of value per month: 2,087
• Shrink and damage at 1.5 per cent of the extra stock: 1,512

Expressed as a return, that is 9.3 per cent on the average additional investment over 4.6 months, or roughly 24 per cent annualised. On those numbers, yes, borrow and take it.

Where it flips

The arithmetic is robust to the cost of money and fragile to everything else.

That is the honest summary: you are not being paid 7 per cent to borrow money. You are being paid 7 per cent to take inventory risk, and the financing cost is the small part.

Two framings that mislead

What makes it safe or unsafe

Safe:

• A staple product with a stable, measured sell rate over at least a year.
• No expiry, no fashion cycle, no version numbering, no seasonality mismatch.
• Storage you already pay for and do not fill.
• A supplier price that is not about to fall.

Unsafe:

• A product whose demand you are estimating rather than measuring.
• Anything perishable, dated, or subject to a model refresh.
• Stock that displaces a faster-moving line on the same shelf or in the same racking.
• A discount offered because the supplier is clearing it, which is information about future demand.
• A 20-week order for something you sell in unpredictable bursts.

The displacement question

If the extra stock occupies space or capital that a faster-selling product would have used, that opportunity cost belongs in the calculation and usually exceeds every other line. A line turning four times a year at 40 per cent margin generates roughly 1.60 of gross profit per dollar of inventory per year. Fifty thousand dollars diverted from it for five months costs about 33,000 of foregone gross profit — several times the discount.

Most small businesses are not actually capital-constrained in that way at any given moment, so the displacement cost is often zero. But it is worth checking rather than assuming.

Financing structure

• A revolving line is the right instrument, because the requirement falls as the stock sells. Borrowing a fixed sum on a fixed term means paying for money you have already recovered.
• Avoid fixed-total-repayment products for this. A discount of 11,200 against a product where early repayment saves nothing is a bad pairing. See what early repayment saves on each product type.
• Check availability first. If taking the discount uses your entire line, you have exchanged a 4,700 gain for the loss of your only flexible facility for four months. That trade is usually bad.
• Consider supplier terms instead of borrowing. A supplier offering 7 per cent for volume will sometimes offer 60 days instead, which achieves most of the same effect for nothing.

The five-minute test

1. What is the discount, in dollars?
2. How much extra cash goes out, and what is the average amount tied up over the period?
3. What does that cost to finance, store and insure, plus expected shrink?
4. What sell rate am I assuming, and is it measured or estimated? Rerun at half the rate.
5. What share of the extra quantity would have to be unsold for this to be a loss? If that number is under 10 per cent, the discount is a bet on demand, not a saving.

Ask the supplier for the same discount on a smaller quantity with a commitment to reorder, or for extended terms instead. Either gets you most of the benefit without the inventory risk, and the worst they can say is no.