I take the attitude that it is not the upfront cost of a material item
that really "costs", but its depreciation between the point I buy it
and the point I sell it again.  With this in mind, I generally tend to
try to minimise rates of depreciation, eg. by buying second-hand. 
However, I find it quite difficult to estimate the depreciation curve,
especially of fast-depreciating electronics goods.

I was wondering, therefore, whether there exists a web site that
offers graphs of resale value of a given product over time, preferably
taking its source data from an auction site like eBay?  Even better,
it could offer a prediction of the future depreciation curve by using
an average of other similar products (that is, those with similar
deprecation curves).

Failing that, where can I find generic (but up-to-date) depreciation
curves for a wide range of consumer goods, including electrical items
such as cameras and computers?

Cheers,

Jon

The web site www.nextag.com provides price history graphs for consumer
electronics products - just enter the model number.  See for example
Vtech VT-2420 2.4 GHZ phone, price history graph from product
introduction (year 2000) to present.  Shows price spikes for product
promotions, as well as trend lines over time.

Price erosion over time can be dramatic.  The Sony DVD player which
cost $400 in the year 1999 can be replaced with an off-brand DVD
player for $40 in 2005 -- plus the $400 Sony can't reliably play
dual-layer DVDs, so it might sell for $5 in today's market.

Cheers Larry, I saw that a while back but couldn't remember the
address!  Thanks for reminding me.

Unfortunately I'm a miserly bastard who usually buys second-hand - so
most of the products have gone off those graphs before I've even
bought them, let alone thought about selling them on.

Cheers,

Jon