[thejeff]

Many products don't drop in price over time, if we're talking about product lines as opposed to actual things. Sure, two year old cars are cheaper than this year's model, but that's because the actual thing is two years old and used and thus is not likely to last as long. If they just keep making them to the same design the price doesn't drop.

Clearance sales and discontinued products aside, furniture stays at about the same price as long as it's being produced. Chairs that were designed 2 years ago aren't half the price of this year's chairs.

Electronics are a special case. The same specs do keep getting cheaper, but that's because the tech keeps getting better. Not only do higher performance versions keep coming out, but it gets cheaper to make the lower performance hardware. Software often follows this pattern, since new versions keep being made to exploit the new hardware.