Collections of Pez dispensers, paintings, or old Porsches can sometimes turn out to be profitable investments.
But if you're a collector for whom there's no real enjoyment without earnings, then the "tangible assets" game is not for you.
Cars, in particular, don't often make the grade. They're the kings of depreciation.
Still, consumers crave them not just as appliances, but also as accessories. Enough Americans care about cars that despite a tough economy they've fueled what USA Today recently called a "road candy" trend.
That's the purchase of flashy third or even fourth cars, often something fun, like a convertible.
Some drivers may let quirky older cars play this role. I own a 1979 Fiat, described in this space before. Eric Evarts, who wrote this week's lead story, recently bought a 1970 Volkswagen Beetle that he's been trying to get past a tough Massachusetts inspection.
We'll both undoubtedly sink more money into our "classics" than we'll ever be able to extract.
Drivers who go an extra mile and buy true collectibles (see Eric's story for some examples) may find that while the vehicles are costly to maintain, the expenses can be less than for a commuter car.
Less regular upkeep is needed on collectibles, as long as they're not driven too much or too hard, and storage conditions are good.
And many insurers offer breaks on "antique" cars usually defined as more than 30 years old. (Policies usually carry rules about mileage limits, where the car is stored, and how and where it's driven.)
All of that can lead to eventual resale with little financial loss if the car is a model in demand. It may even lead to some profit-taking.