...I was just thinking about this...

For the most part, I'm happy with what I purchase. So, what drives me to sell is just a lack of space. It is sometimes hard to sell something, because I'm not motivated by distaste for the model. So I sell begrudgingly, and it is hard at the time I make the decision to sell. But, so far, I am not unhappy after I clear the space and money goes into my pocket.

Your story is much different, though. I'd like to have that Sauber Mercedes you described. :)