When not to undercut in the market - when you make up the second of a pair

My golden rule of competitive counter pricing

When i come to review the items i have for sale by default action is always to be the cheapest.

Of course, that erodes the margin i end up selling an item for and could eventually mean i sell an item at a loss.

But my main driver is to convert an item i have for sale into ISK so that i can reinvest it in the market.  I am a Trader, not an Investor.

The last thing i need is a growing list of items i have for sale that are undercut by so many competitors that they will never be sold.

There are some exceptions to this default action and one of them is when i have been undercut by a competitor in an item that typically sells two at a time.

A great example is mining turrets.  They typically sell two at a time.  Hence, if i have an item for sale for, say, 300m and someone else comes in at 299m for one item then i won't move my price.  When the Buyer comes along they will buy the competitors item first and also mine.  Hence i save the re-listing fee and lower selling price.

Better still if that person puts the item up for sale at 250m instead.  Then the Buyer will mentally calculate the average price they are paying which means they will calculate that they are paying an average price of 275m for my item which is up there at 300m!

The easiest way to determine the typical volume per purchase is to look at the volume data in the market.  It is very obvious straight away if this is an item that sells individually, in 2's, 3's or 4's or random.  And of course, having an understanding of the use of the item is a big held.