they probably bought the plates before you knew how to drive.
but yes, there is lots of money put into these cars. i would like to build a 1933 ford 3 window coupe, but i am looking at about $15,000 just for a rusty old shell with no motor, running gear, etc. and it isn't just a case of bolting stuff in. you have to custom make a front and rear end for it, then custom fit brakes, and steering, then custom make all the interior, the list goes on. my father-in-law does it for a living, so i know how much shit there is too it, and they mainly do F trucks, which are easy ones. but they still take about 2-3 months work (thats working 5 days a week on it).