What Does the Parable of the Two Debtors Mean?

Clean Cut: Episode Directory
nameunderheaven...
Clean Cut; Episode 540
How much did each of the debtors owe? What do the different debts mean? What was slavery in ancient Jerusalem?
All well-reasoned comments welcome.
If you're new to the series, I hope you'll check out the previous episodes, as they contain a lot of deductions, which I'll be building on.