What does 'lazy' mean in the sentence 'They bought the mansion for a lazy $10 million.'?

It seems to me that 'lazy' in this context suggests a humorous, off-hand attitude to a sum most would consider serious money. Is it a jocular minimisation of the amount, almost the opposite of the maximisation implied in 'a cool $10 million'?

It's not impossible to construct a sentence that, in context, uses "a lazy $10 million" in a meaningful way, but the phrase seems not to be an established English idiom. Google Books searches for the phrases "a lazy sum" and "a lazy amount," for example, turn up no matches in the Google Books database.

Here's a scenario where "a lazy $10 million" might work:

In going over their portfolio, Don and his then-wife realized that they had tens of millions of dollars sitting around doing nothing—neither accumulating interest nor appreciating in value. So they began looking at investment properties and found a large house that appeared to be worth more than the asking price. After some pro forma dickering, they bought the mansion for a lazy $10 million.

In this situation, you could characterize the $10 million as lazy because it wasn't increasing in value until converted into a deed to the mansion. But as I said, this is a one-off invention; as far as I know, the phrase "a lazy $XXX" is not an English idiom.