I think "poverty mentality" is much less offensive than "stingy' or "greedy". My grandmother had a "poverty mentality". Even when she had grown up, acheived an education and a career and then married a successful businessman, she always saved every bit and scrap of everything. She saved string, paper bags and washed and re-used tinfoil. She'd press soap scraps together to avoid throwing away even the tiniest bit of soap. She would agonize over wasting any food, even to the point of eating things that were on the verge of spoiling. She refused to let her kids take out car loans. I mean, she had good points and could certaily squeeze every bit of life out of a dollar but it overall was bordering on pathological anxiety. She was constantly worried about people taking from her, she would say scathing things about people on assistance (because she had pulled herself up by her bootstraps, after all) and she hoarded things to the point some rooms in her house became unusable.