Mike, it sounds like we think the same way when it comes to collecting. I consider a rarity at less than perfect condition for the right price to be an acceptable acquisition, but if it's a book, author or edition I really love, I'll upgrade when that opportunity arises.
Not so much PC versus numbered, personally. I won't pay the same for a PC as a numbered/lettered, but I don't feel the need to update a PC edition.
HBJ