Purpose
[This feature was removed on eBay's request. Completed auction data is licensed.]
Completed Stats lets you search completed auctions by title. Prospector then analyzes the results and provides summary statistics. You can use this to get a feel for a market and what items are selling for.
Access
This search is available through the Quick Search Toolbar.
Select Completed Stats as the Search Type, provide a title search, and click Enter.
Notes
Only the items denominated in the eBay site's currency are considered.
Completed Stats won't fetch more than the number of items specified in the Tools menu / Prospector Options / Search tab / Max items to show per search.
The Standard Deviation is an estimate for how widely dispersed the values are from the average value.
The "% error of mean" gives some sense for how well the average represents the set of numbers - the smaller it is, the better. If it is very large (say 100%), it may be because your search is picking up items that are different, and refining the search may be called for.
The "95% confidence interval" is a range on both sides of the average that gives this degree of probability that the real average is contained within. Like the "% error of mean", this can be used as an error measure to help with creating more accurate statistics.