i'm not one much for doubles--never did that, i would jsut borrow it from someone--but otherwise, i find it does keep me thrifty. first, i think about everything before it comes in, so that keeps me from purchasing, and second, i wonder if i can borrow it, buy it second hand, or some other such thing.
it is true that sometimes organization systems require some up front costs, but not always. i'm surprised, for example, how many little organizing things i can make or find for free at a thrift store, or just on the street. seriously, it's amazing how much i can find on freecycle!
anyway, yeah, i couldn't give you the actual dollars and cents, but it does save cash.