When Jareth killed his fake family members in the Blaze mansion, he picked up their space rings, in which he found the 'Family Card'.
A family card serves as a unique 'ATM' card for making purchases under the family's name.
Jareth immediately sent a large amount of money into his own bank account using the ATM card, never pausing until it was completely full.
Now the Blaze family will have to pay all that money to the bank, as all that was a credit taken in the name of the Blaze family.
The Vassal families will have to bear the consequences of this action.
They are currently looting the family resources, but they don't know that they are already millions in debt.
Even their own companies and businesses will soon go bankrupt to pay this massive sum of money that Jareth has added to his own bank account.