Fetishism. A phenomenon that occurs mostly to males in Western societies with a comfortable disposable income. The focus of the affliction usually centers on mechanical objects of some sort; cameras, watches, fountain pens, knives, etc. Acquisition of said objects lies outside the realm of the practical and is not necessarily limited to items narrowly defined as collectible. When the affliction strikes females it is often focused on handbags, shoes, coats or other garments but females are not immune from typically male symptoms and vice versa.
Personally, I am fortunate that I've been spared largely from this affliction, though I do have 5 or 6 pocket knives. Oh, and I used to be obsessed with fancy goldfish. Had 3 huge aquaria and many beautiful oranda, ryukin, black moor, etc.