Question About a Passage

In chapter 34 on page 273 Pip mentions the way his lavish habits have affected the Pocket family, and Herbert especially, saying "My lavish habits led (Herbert's) easy nature into expenses that he could not afford, corrupted the simplicities of his life, and disturbed his peace with anxieties and regrets." But follows on the next page to say that "as an infallible way of making little ease great ease, I began to contract a quantity of dept. I could hardly begin but Herbert must begin, too, so he soon followed."

My question is why does Pip get himself and Herbert into further dept in response to realizing it's negative affects on his friend? And how is contracting more dept a way to make "little ease great ease"?