Yeah that is very true. The impulse buys is what kills your enjoyment.
Recently I bought an FOC Onslaught and FOC Swindle in a misguided plan at customizing them into game colors to be able to turn my G2 set into something closer to the game at will. Once I had them in hand and begun to play around with possibilities. Then I realized that they were never going to look good without having to redo the G2 set (which colors I like). I wasn't prepared to do that so regular FOC Swindle and Onslaught became superfluous making me regret the buy.
That is the only two TF toys in the last 2-3 year that I have regretted buying and it is a crap feeling. I can't imagine how it would be for someone who constantly impulse buys and ends up with bulks of unloved toys.