If you are anything like me, you don't always want the whole set, just some of the parts. I typically don't buy red or blue sets mainly because all of my creations are yellow, black and grey. It is VERY clear to me that TLC knows exactly how to make me pay $60 for just a few parts. Yes, I do own several red and blue sets, but unless it is a Supercar or something, it typically doesn't get built, it just gets inventoried and put away...red and blue in my "won't use again" stock and the rest in my active stock. Thank goodness for all the inventories on BrickLink.
Just to prove the Lego forces us to buy stuff we don't necessarily want, take this video done at BrickCon recently about the new "collectable minifigures." DARN YOU, LEGO! It's funny but has some brief adult language.