Is the "History" tab a list of:

1. Prices of auctions that went to completion because the item sold?
2. Prices of auctions that went to completion whether or not the item sold?

In short, when a price appears in the history tab, is it a guarantee that the item was successfully sold at that price in the past?

Its and average between the lowest low price and the highest low price for that day (in case of multiple scans a a day)

itemPrice = zc.round ((highlowprice + lowlowprice) / 2);

And no it doesn't guarantee that the item was sold

Thanks for the answer @manzarek123!