How often Amazon prices change, and what that means for your eBay margin

How often do Amazon prices change?

How often Amazon prices change has no single answer: some products move several times in one day, others hold the same price for weeks. What decides the pace is how many sellers compete on the listing, how much stock each has, whether a deal is running and what time of year it is. For an eBay seller who prices from Amazon, the useful question is narrower: how often do the products you list change, and is your checking schedule fast enough to keep up?

Amazon does not publish figures on price changes. Any number you read claiming to describe every product is a guess. The answer that matters is the one you measure on your own catalogue.

Why do Amazon prices change so often?

An Amazon product page is a marketplace in miniature. Several sellers can offer the same product, and the price you see is the price of the offer that currently wins the buy box, the box with the main Add to Basket button. Several forces move that price.

Seller competition

When many sellers offer the same product, they adjust their prices against each other, often with software. Each adjustment can change which offer wins the buy box and so the price shown to you.

Changes in the winning seller

The displayed price can move even when nobody has changed their own price. If the seller with the lowest offer runs out of stock, the next offer takes the buy box and the price jumps. When the first seller restocks, it can fall again.

Stock levels

Low stock, especially on Amazon's own offer, can be followed by a higher price or a slower delivery estimate. A product going out of stock entirely removes the offer you were pricing from.

Deals and promotions

Time-limited deals, coupons and voucher offers lower the price for a period and then end. A listing priced during a deal can be underpriced the moment the deal finishes.

Sale events and seasons

Events such as Prime Day and Black Friday bring many temporary price cuts. Gifting seasons can push prices on popular products up as stock tightens.

Where you are delivering to

Amazon picks the winning offer for a delivery address. A different postcode can show a different seller, delivery charge and price, which looks like a price change if you read from two locations.

Which products change price most often?

You will usually see more movement on some types of product than others. Use this as a guide to where to look first, not as a rule.

How do you measure how often Amazon prices change on your products?

You do not need a study. You need a log. Every time you read a product, record the price, the delivery charge, the seller and the time. After a couple of weeks you have enough to see the pattern.

1. Log every reading. Keep the time, the price including delivery, the seller and the stock status.
2. Count the changes. For each product, count how many readings differ from the one before.
3. Work out a change rate. Divide changes by readings. A product that changes on half its readings is moving faster than you check it.
4. Note the size of changes. Frequent changes of a few pence matter less than rare changes of several pounds.
5. Group your catalogue. Put products into fast, medium and slow groups and give each group its own check interval.

A hypothetical example

Example: suppose you read a kitchen gadget 20 times over 10 days and the price differed from the previous reading 9 times. Its change rate is 9 in 20, or 45%. A second product, a niche spare part, changed once in 20 readings, a rate of 5%. The gadget needs checking several times a day. The spare part can wait for a daily check. Spending your checks where the movement is gives you fresher prices for the same effort.

Is it a real price change or a reading error?

Not every difference between two readings is a real change. Before you act on a big movement, rule out the common false alarms.

• A different variation. A product page with sizes or colours can open on a different option, and each option can have its own price.
• A multipack or bundle. A pack of three read as a single item looks like a price tripling.
• A different delivery address. If the page was shown for another postcode or country, the offer and currency may differ.
• A used or renewed offer. If the new offer is out of stock, the cheapest offer left may be used, which is not the same product condition you list.
• No buy box. Some pages show offers from other sellers but no main buy box. A number taken from such a page is not a like-for-like price.

A quick rule: if a reading moves more than your usual swing for that product, read it again before changing anything on eBay. A genuine change will still be there on the second reading. A glitch usually will not.

What does a price change cost you on eBay?

The cost of a missed change depends on its direction.

• A missed rise means you sell at a price based on the old cost. Each order earns less than you planned, and a big enough rise turns a profit into a loss.
• A missed fall means your eBay price sits higher than it needs to. You lose sales to sellers who reacted faster, though each sale you do make earns more.
• A missed stock-out means you take an order you may not be able to fulfil within your stated handling time.

Example: suppose you sell 10 units a week of an item you priced from a £15.00 cost, and the cost rises to £16.50 for three days before you notice. If you sold 4 units in that time, you gave away £6.00 of margin before fees, and the fee on each sale was charged on a price that no longer covered your cost. On a thin margin that can be the whole week's profit on the item.

Because you source from Amazon, remember the policy side too. Under eBay's drop shipping policy, dropshipping from a wholesale supplier is permitted, but listing an item and then buying it from another retailer or marketplace that ships directly to your buyer is not allowed. You are responsible for delivery on time and for your buyer's satisfaction whatever your supply chain.

How should you adjust your pricing for products that change often?

Once you know which products move most, change how you handle them.

• Check them more often. The faster a product moves, the shorter its check interval should be.
• Use a wider margin. A bigger buffer absorbs a rise between two checks.
• Set a profit floor. Never let a reprice take the price below the point where you still make your minimum profit.
• Re-read after every sale. The next buyer should get a price based on the current cost.
• Hold big swings. A sudden large change is worth a human look before it goes live.

A repricer can do this on a schedule. Dropizon reads the Amazon buy box in a browser tab on your own computer and reprices from each reading with your own formula and floor, and the eBay repricer page explains how the checks and holds work. For a view of how individual Amazon UK products have moved over time, the Amazon UK price comparison and history is a useful starting point.

What to do next

• Start a reading log today, even a spreadsheet, with price, delivery charge, seller, stock and time.
• After two weeks, work out a change rate for each product.
• Sort products into fast, medium and slow groups and set a check interval for each.
• Widen margins on fast movers and set a minimum profit floor on everything.
• Read eBay's drop shipping policy and check your sourcing model against it.
• Review the groups monthly, because products move between them as competition changes.