An object that may have had an original purpose (usually electronic devices) or a concept model of something else, but in any case unable to serve its intended purpose except as a display item or a paperweight
Since many of these paperweights, especially those of the old electronics category, required a larger investment at its initial purchase, these paperweights become expensive, hence, the "expensive paperweight"
I found an old ipod in my uncle's basement, but it doesn't even work anymore so now it's just an expensive paperweight!
Is that a BlackBerry?
It WAS a BlackBerry, now it's just an expensive paperweight!
Whoa is that seriously a holographic infrared keyboard?
Nope, this is just the concept model for a holographic infrared keyboard that got rejected during the pitch... So now it's just an expensive paperweight!
Phrase perfected by Marv Albert, referring to a basketball game in which the winning team's lead is so great, that the mere phrase "garbage time" does not do it justice. This is the part of the game where both teams have emptied their benches and are playing out the clock, but even more so than in just conventional "garbage time."