So what's old Dorrit like with money? Well, pretty much the same as without money: egotistical, conceited, snobby, and generally thoughtless.
He spends his last few days in prison (while all the logistics and paperwork and stuff is dealt with) putting on airs in front of as many people as he can.
He orders fancy clothes for himself, Fanny, Tip, and even his brother Frederick.
He pays everyone back in the most obnoxious and self-important way possible.
He gives out charity to the other prisoners, then lectures them at length.
He starts acting like some kind of Lord of the Manor, with all the other prisoners his tenant farmers. He orders them a feast and watches them from on high.
It's sad and funny and mostly pathetic.
Finally, the day to leave arrives. Dorrit and Frederick take one last stroll through the prison yard, and Dorrit tells his brother that he is preoccupied with worry: "I find that I think, my dear Frederick, and with mixed emotions in which a softened compassion predominates, What will they do without me!" (1.36.26).
The other prisoners wish them well and seem to be doing just fine without Dorrit.
The Dorrits pile into their carriage and drive out.
Suddenly Fanny realizes that they're missing Little Dorrit.
They see her being carried to the carriage by Arthur, still wearing her raggedy prison dress. Well, that's some passive aggression right there. Why wouldn't she change her gross old clothes?
Fanny is furious at this insult to the family honor, but when Arthur walks up he says he found Little Dorrit passed out while in the process of changing into her new clothes.
Fanny immediately feels bad and starts to take care of her sister as the carriage drives away.