Let us consider the character of Pip and how he changes straightaway when he finds out about his great expectations at the end of Book I. Pip, almost overnight, becomes something of a snob, and does not want to be publicly seen associating with characters that love him and have done so much for him. In particular, he explains that he is unable to sleep in his old bed peacefully as he was wont to do. Lastly, at the very end of Book I, as he goes off to London, there is a deliberate allusion to Paradise Lost when Satan contemplates earth for the first time:
And the mists had all solemnly risen now, and the world lay spread before me.
The combination of the mists rising seems to symbolise Pip's inability to see clearly. This, coupled with the allusion, suggests that the newfound wealth of Pip is not a positive thing.
If we examine the way that London is described, and in particular Barnard's Inn, where Pip is to stay, we can see how this impression is supported and confirmed. Note how Barnard's Inn is introduced and the kind of impression that it creates both of Pip's great expectations and London, the city of wealth:
We entered this haven through a wicket-gate, and were dis- gorged by an introductory passage into a melancholy little square that looked to me like a flat burying-ground. I thought it had the most dismal trees in it, and the most dismal sparrows, and the most dismal cats, and the most dismal houses (in number half a dozen or so), that I had ever seen.
It is dilapidated and run down and destroyed, and clearly foreshadows the moral dilapidation that is to occur in Pip as he becomes a man of expectations and uses that wealth to get himself into debt, drink, and engage in other unsavoury activities. Pip is the prime character that demonstrates the corrupting influences of wealth in this novel.