Tales of Destiny listing above sells, eBay will show the sales price as $59.99 when in fact the buyer actually paid $47.39.
If you were using this listing as a reference you would think Tales of Destiny sells for $12 more than it actually does.
We record the actual sales price in our database so using our historic data as your reference eliminates this upward bias.
We discovered this during our regular pricing audits. We record the ACTUAL sales price every time an item sells. Every time you visit one of our completed auction tabs eBay tells us the price for each listing again. We manually investigate any prices that don't match in order to fix any errors.
This same issue also happens listings sold in another currency. eBay changes the sales price to reflect the current exchange rate instead of the exchange rate at the time of the sale. This doesn't change prices as much as the sales do, but it does make the completed auction listings on eBay inaccurate. For example, the exchange rate between US dollars and Canadian dollars increased 7% during the last 90 days. So all Canadian eBay listings from three months ago will be off by 7%.
Again, we record the prices based upon the original exchange rate so it matches what the buyer actually paid for the item.