The conclusion: summing up parts 1, 2, 3 & 4.
If typical, the rich man in Luke 16 already had plenty of money. His personal share from his fields was over one thousand bushels of grain, after harvest. His oil pressing facility was turning over almost a thousand gallons of oil in pure profit. Keep in mind, such a man could have easily been collecting from loan interest, rental income and perhaps other ventures as well.
At any rate, these fields and this oil press alone had been yielding such bounty for years upon years. Such rich men did not become wealthy overnight, and it would more likely have been one's father or grandfather that purchased a farmland and a press, and invested in both for some years, producing surpluses after attaining fairly regular profitability.
This explains why, at all points in Jesus' parable, this rich man clearly had NO desperation about collecting on these late payments. And that matters immensely.
Recognizing his comfort helps us see the larger point. A successful rich man knew that reducing his income from one year of profit was a very small price to pay for the much larger benefit of rehabilitating his steward. Good help is hard to find. Thus, finding out that his formerly lazy (or laizzez-faire?) steward had finally discovered the vital necessity of social interdependence - THAT was the prize, for the rich man. Once the top level manager understood the importance of managing relationships with the landowner's onsite contractors, everything else could be worked on.
In other words, wealthy people stay wealthy by taking the long-term view, and that's just what explains the odd twist this time in Jesus' parable. None of us survive in the long-term by relying on diligence and efficiency. Long-term, we must learn to rely on others.
The wealthy landowner used his profits in good years to secure good favor with other wealthy friends, as a store house of good will against possible times of great need.
The contractor-debtors worked on site all year long for the benefit of the master whose wealth would provide for them always, as long as they kept proving loyal.
The steward had finally realized that serving the landlord meant taking good care of his contractor-debtors. His job wasn't just about picking up dues and enforcing the rules. It was about treating those on-site workers themselves like the living and valuable assets they were.
Whatever else Jesus was aiming at with the parable in Luke 16, we can at least observe this much. All of these people leveraged their earthly resources to improve key relationships that affected their futures. Surely, that's what the master wanted to see happening - all his associates investing in everyone's long-term well-being, together.
Just as surely, Jesus had BOTH lifelong AND Eternal perspectives in mind whenever he shared this perplexing parable with the crowds he encountered. We can also sacrifice earthly resources to get in good with Him who holds the ultimate long-term.
We are all stewards of resources entrusted to us.
We can all become better investors in God and in others.