I never bought the set. I have to say that for people looking at getting one, especially brand new in the box, think of the value and what goes into each piece of the set. Separate the car's and the engines price's, and to me it seems like a good value. I just never have that spare cash laying around. You can't buy each piece, one at a time.
I have to believe, that there's defects/quality man. issues, also included (factored) in the comments above. Comes with the attempt vs. QC.