The Buy Box repricer uses one store-wide floor and ceiling, expressed as percentages of your Shopify price. That works well for a catalogue with roughly consistent margins. It works badly for the products that are exceptions. A per-product override lets you give a single product its own hard price limits, in real money, and have the repricer respect those instead of the percentages.
Overrides live on the product detail page, which you reach from Product Sync by opening any product. Scroll to the repricer override section and you will find two fields:
Both are entered in the marketplace currency, not as percentages. If you sell into a marketplace whose currency has no decimal places, such as Japan, enter a whole number.
Below them is Reprice this product now, which runs the repricer immediately for that one product using the values you have just saved. This is the fastest way to check that an override behaves the way you expect, without waiting for the scheduled run and without repricing your entire catalogue.
The rule is simple, and it is worth stating plainly.
A per-product override beats the store-wide percentage rules. When the repricer resolves the band for a product, it looks for an override first. If one is set, those absolute values become the floor and the ceiling for that product, and the Price floor (min) % and Price ceiling (max) % on the Repricer screen are ignored for it entirely. Only if there is no override does the repricer fall back to the percentages of the Shopify price.
Everything else about the algorithm stays the same. The strategy, the undercut amount and the schedule are all store-wide, and they still apply. The override changes only the band the target price is clamped into.
A product with no resolvable band is skipped
If a product has no per-product override, and no percentage band can be resolved for it (for example because it has no usable Shopify price to take a percentage of), the repricer skips it entirely. It is not repriced with a default, and it is not pushed at some fallback price. It simply does not participate, and it shows up in the skipped count in the last-run summary.
If a product you expected to be repriced keeps landing in skipped, this is the first thing to check.
A product with unusual margin. Most of your catalogue might tolerate a floor at 85% of the Shopify price. A product where you buy at 80% of retail cannot. Rather than raising the store-wide floor and blunting the repricer everywhere, set a Min price on that one product at a figure you can actually afford, and leave the rest of the catalogue alone.
A loss-leader. If you deliberately want to be the cheapest offer on a particular ASIN, and you are prepared to go well below your usual margin to do it, the store-wide floor is in your way. Set a Min price on that product at the true bottom you are willing to accept. The repricer will then undercut competitors all the way down to it.
A high-value item where a percentage band is too wide. Percentages scale, and on expensive products they scale alarmingly. A floor of 85% on a product priced at 40.00 gives you six pounds of room. The same 85% on a product priced at 1,200.00 gives you 180.00 of room, which is a great deal of margin to hand over automatically. Give expensive products explicit Min price and Max price values, chosen in cash terms, so the band is as tight as the product actually warrants.
Set both fields, not just one. An override is a band, and the repricer needs both ends of it to clamp against.
Remember that overrides are absolute figures, so unlike the percentage rules they do not move when you change your Shopify price. That is exactly the point, but it is also the maintenance cost. If you reprice a product in Shopify and it has an override, revisit the override, because it will otherwise keep enforcing a band that was set against the old price.
Check the Amazon fees card on the same product detail page before you choose a Min price. It shows Amazon's own estimate of the referral fee, closing fee, per-item fee, FBA fulfilment fees, total fees and net proceeds at the current price, which is a much better basis for choosing a floor than a round percentage.
Tip
Only products published through Product Sync are repriced at all. If a product does not have a listing you own on Amazon, an override on it does nothing. See the warning in the Buy Box repricer article.