Lets say you are the sole owner of the stock of chip X and your current retail price is $100. All chips are in equal condition.
You have been selling one a month on ebay and your prices achieved (oldest first) are:

$2000 (high because it was the first one known)
$500
$250
$150
$100
$100
$90
$80
$70
$68
$66
$64
$62
$20 (because the auction ended at 4am on a holiday and people missed it)
$60
$58
$56
$55
$54
$53

The average ebay price is $196. What do you think the catalog value should be?