You must have heard something called “Winning a Buy Box” on Amazon. If any of your products happen to win this, buyers looking for that item are shown your product first even if your price is higher than others giving better opportunity for sale.
In an example above, you can see Concord Extra (£7.04) got privilege to sell an item which is penny higher compared to Jons Gifts (£7.03). Buyers looking for this item see this item first to Add to Basket. There is a general assumption on Amazon that cheapest item is shown in the top, hence customers end up buying that item.
It does make a difference if you win Buy box or not. There is no other way to win a buy box than being a Good Seller. Being a Good seller means shipping orders on time, fewer refunds, and fewer cancelled orders apart from lower price of the item. Amazon got very comprehensive Seller Performance Reports which you simply need to keep an eye on.
You might have read expert articles on this subject, but Remember the bottom line is be a Good Seller and you will win Amazon Buy Box.