Your Supplier Raised the Price.
What Should Happen to Your Listing?

The loss nobody tells you about

When a supplier runs out of stock, you find out — an order comes in and you can't fill it. It's painful but loud.

A price rise is silent. The item you sourced at $12.40 now costs $17.90. Your eBay listing carries on at $24.99. It keeps selling. Every sale looks like a sale. eBay reports revenue, your dashboard shows orders, and you are losing money on each one.

Nothing in eBay's interface will ever tell you this. eBay knows what you sold it for. It has no idea what you paid.

Sellers usually discover it at the end of the month, when the bank balance disagrees with the sales figures. By then it has happened forty times.

How much does a rise actually cost?

More than the price difference, because eBay's fee is charged on the sale price and does not shrink when your cost grows. Work an example on a UK listing at £24.99 with £3.99 shipping charged to the buyer:

Line	At source cost £12.40	At source cost £17.90
Buyer pays (item + shipping)	£28.98	£28.98
eBay final value fee (13.25% of total)	−£3.84	−£3.84
Fixed order fee	−£0.30	−£0.30
Your postage cost	−£3.20	−£3.20
Source cost	−£12.40	−£17.90
Net profit	£9.24	£3.74
Margin	32%	13%

A £5.50 cost increase — 44% on the source price — took 60% of the profit. Add promoted listings at 5% and the remaining £3.74 becomes £2.29. Add a single return and the item is negative for the month.

This is why a flat "assume 15% fees" rule is dangerous. It is not far off on a healthy margin and completely wrong on a squeezed one, which is exactly when you need it to be right.

The four possible responses

There are only four things you can do, and choosing between them is a business decision, not a technical one.

1. Raise your eBay price

The obvious answer, and often correct. The constraint is that eBay is a comparison marketplace: if your price moves above the competing offers, your conversion rate drops and Best Match follows it down. Raising price is free only until it isn't.

2. Accept the thinner margin

Sometimes right — a fast-moving item at 13% may still be worth more to you than the shelf space it occupies, especially if the rise looks temporary. This is a decision, though. It should not be something that happens to you by default.

3. Pause the listing

Set quantity to zero, wait for the price to come back. Correct when the rise looks like a spike, and it protects you from selling at a loss while you decide. It should never mean ending the listing — that destroys its sales history, ranking and watchers for good.

4. Re-source the item

Find another supplier at the old price. Highest effort, and the only response that fixes the problem rather than reacting to it.

Where the line should sit

Two thresholds are worth defining before you need them, because in the moment you will guess.

The alert threshold

How big a move deserves your attention. Percentage works better than a fixed amount across a mixed catalogue: $1 is nothing on a $90 item and fatal on a $6 one. Around 5% is a sensible starting point. Below 2% you will be reading noise — supplier prices move constantly by small amounts.

Watch the direction that costs you money. A price fall is an opportunity to reprice, but it is not urgent; a rise is eating margin right now.

The stop threshold

The point where selling is definitely wrong regardless of your judgement. The cleanest version needs no fee table at all:

If supply cost has reached or passed your eBay selling price, you are losing money before a single fee is counted. Stop selling. There is no argument on the other side.

A full version uses your target margin — stop when net profit after all fees falls below your floor — but that requires the fee maths to be right, per category, per currency. The absolute version is a safety net that is never wrong.

Watching without doing it manually

Checking supplier prices by hand does not survive contact with a real catalogue. At fifty products it is an hour a week you will skip. The check has to be automatic, and three things determine whether it is useful:

• It must know what you originally paid. A price is only meaningful against a baseline. Store the cost at the moment you sourced the item, so the drift is always visible.
• It must not re-alert on the same change. Tell you once that $12 became $14. If it climbs again to $16, that is new information and deserves a second alert — but the first one should not repeat every hour.
• It must be honest about staleness. If the last reading is three days old, that needs to be visible, not presented as current.

How ArbiKey handles it

ArbiKey stores the supply price at the moment you import a product and monitors it afterwards. The product list shows the drift on the row itself, so it is visible while you are doing something else rather than buried in a report.

The certain-loss guard implements the absolute rule: when supply cost reaches or passes your eBay price, quantity goes to zero — the listing is paused, never ended — and it is recorded in the decision log with the reason. Every threshold around it is yours to set, and practice mode records what would have happened without touching eBay.

Underneath all of it is the profit engine: the eBay final value fee for that item's exact category, the international fee, ad rate, VAT and the day's ECB exchange rate. The number that triggers an automated action is the same number you read on the order.

Common questions