I was reading a short story named "The Pleasant Surprise" by Barry King ; the first three sentences read
"I had got the money by work done at home, out of office hours. It came to four pounds altogether. At first I thought I would use it to pay back part of our debt to Eliza's mother."
My question is, is the past perfect really necessary here? If the writer hadn't used the past perfect where he did, would it make a difference meaning wise? And I say this because the events are conveyed chronologically here.