Like any other price reference, the information is dated as soon as it hits the printers.
I've got an '02-'03 copy that came with the mini lllf digi cam & sold off the camera. By doing that I got a serious discount on the book.
At over $100 it seems a bit much. When film was more popular in retail it was a good reference for the oddball stuff. Common equipment was simply figured at about 30-50% of retail depending on rarity. I don't know if he's kept up with the recent depression of prices since digital has become more popular.
It is still an interesting book to look through & if you pick up an older copy it's no great loss of information