"Requiring President Trump to post a bond or other security before this Court's ruling on his stay motion threatens to impose irreparable injury in the form of substantial costs (which may or may not be recoverable)," the attorneys wrote.
I wish the judge's ruling would simply quote this part and then say, "Yep." And then the legalese indicating the the request is denied.
(Also -- I actually don't agree that him trying to squirm out of paying means anything in particular about whether he has the money. Delaying and avoiding paying big bills and hoping that if he stalls them enough, they'll go away, has been Trump's MO since the 1980s.)