Where are there examples of the theme "money can buy justice" in particular situations in 'Great Expectations'? Can you give a few examples?
There are several examples that could support your idea. I will give one negative and one positive.
Magwitch tells us of his trial along with Compeyson in chapter 42. They face the same charge of counterfeiting. Compeyson convinces Magwitch that they will have separate defenses, and it becomes apparent that Compeyson’s money buys him a lighter sentence.
And when the verdict come, waren’t it Compeyson as was recommended to mercy on account of good character and bad company…and warn’t it me as got never a word but Guilty?
However we also see Jaggers take a different line in preserving Estella. By giving the girl to Miss Havisham, Estella has a privileged and secure upbringing. Her mother was a murderess, rehabilitated and kept in check by Jaggers by being made his housekeeper.Her father, Magwitch, was also a criminal. Estella is provided for by Jaggers’ engineering. Similarly, Pip is rewarded by Magwitch his benefactor after feeding him on the moors when he was a wretched escapee.