Hoarding is not the same as collecting. In general, collectors have a sense of pride about their possessions, and they experience joy in displaying and talking about their possessions and conversing. They keep their collection organized, feel satisfaction adding to it, and budget their time and money.
Hoarders generally experience embarrassment about their possessions and feel uncomfortable when others see them. Their clutter often takes over functional living space, and they feel sad or ashamed after acquiring additional items. Also, they often incur great debt, sometimes extreme.
This is worth considering--or so it seems to me!
1. From the Anxiety and Depression Association of America; see also this article. I particularly like the expression "ego-dystonic".