There's a two-part question that all of us should be constantly asking: What's it cost, and what's it worth? And the answers aren't always as obvious as you might think.

Let's say you see something, and the price is $1,000 (since that number is easy to work with - and for the sake of argument, let's forget about taxes for now). What does that cost you? If you pay cash, it will cost you $1,000, straight out of your pocket or bank account. That's simple enough. If you can do that, let's still keep it simple, and say you're earning $25 per hour, that means it costs you 40 hours of work (again, forgetting about taxes and deductions), or one full work week. Is it - whatever it is - worth 40 hours of effort to own this thing?