All you need is love, but in Great Expectations love doesn't get you far without a little money. To Pip, there's no question that Estella might love him as a poor blacksmith's boy: he has to make his fortune (or have a fortune made for him). From the outside, though, all this money stuff doesn't look too appealing. Miss Havisham had a fortune, and still appears to have enough of it to set Estella up in style, but she's miserable—and all the people who want her money are miserable too. Meanwhile, the poor blacksmith seems to have plenty of money to settle Pip's debts, and Pip and Herbert are happy making a "sufficient living" by working hard. Is Dickens saying that the only wealth worth having is the money you earn yourself?
Dignity has nothing to do with material possessions in Great Expectations and, in fact, wealth often traps Dickens's characters into making less noble decisions.
Money combats society and promises characters social mobility, or the ability to rise in society.