Each book gets priced by current Wizard standards (mainstream books and the occasional independent titles)
Each book is then visually checked for condition and the price is adjusted appropriately.
The book is recorded with name, issue, condition, price, year of acquisition, acquisition price, current value
(Happily my system updates the prices automatically.)
Once this is all in, I'll take the list of requests I've been getting and search my database and see if the books are in there ;)