markpatric said:
The question is, are they giveaway prices or realistic prices?, I say these giveaway prices are a lot closer to actual worth.
It depends on the content and how it stands up over time.
Bear in mind that not only is there a 'time value of money' but also a 'time value of knowledge'. Both can depreciate or atrophy if unused.
Some material imparts knowledge that is enduring and of long-term value. Other material has material that is only useful short term.
An example of enduring knowledge would be the principles in 'The Richest Man in Babylon' or 'The Millionaire Mind'. Such books with timeless information is probably worth no less than when it was first printed.
A secondhand copy may be a little battered, but this does not devalue the information within, so that is why op-shop books selling well below their cover prices are such bargains, provided the principles remains applicable.
Books written by current gurus are somewhat more time-specific. Examples would be Steve McKnight's 0-130 book (buy a heap of $50k houses in Ballarat) and one of the Fred Johnston books (which made a very strong case for buying in Sydney in 1997). Both books have some general principles that could apply in other markets at other times. But if you bought both books at the time and followed the authors recommendations you would have made a lot of money. Hence though both books have inherent worth, this is somewhat less than when the book first came out.
Other material dates even quicker. For instance stuff on wraps is useless if yields drop or financiers change their lending arrangements. It's a similar story with statistics or detailed market analyses prepared at a certain time.
The use of such time-dependent information mignt well have made some people (not just the seller!) a lot of money at the time. But information depreciation can be almost 100% in a couple of years and (unless it's needed for long-term historical comparisons) the stuff may only be good for keeping warm.
Peter
