Aldo, why would you need to be 12 to play with legos? I'm just shy of 30 and I play with legos.
I have no idea how much I've spent on legos over the years, but I could tell you the weight from the last time I shipped them.

Its just a little under 450lb.

Whomever asked why you would want to model legos in 3d? First of all, Legos are mathematically precise. That makes them easy to model in 3d if you have half a brain. Second, because no matter how hard you try, no matter how hard you search, you might not every really run across an original Lego Space Galaxy Commander (the sexiest lego spaceship EVAR). Third, and finally, when I started with 3d stuff, MLCad, LegoCAD, etc didn't exist. The best you could get were parts libraries for POVRAY. Sorry, pass. Truespace, whilst heavily denigrated on this site, rocks solid for building 3d legos and it certainly beats the pants off of POVRAY for making renders (perhaps not render wise, but easy of use wise).