"I did it, Marty! It took 30 years AND MY ENTIRE FAMILY FORTUNE but I did it!" - Doc Brown to Marty McFly - BACK TO THE FUTURE.

Doc Brown was a millionaire in 1955 and a pauper in 1985.

Got to pay attention to the movie more. Doc Brown was a scientist of utmost unbelievable ethics - very old school, typical 1950s PhD. Doc Brown is the most ethical scientist in that version of America and he spent his own millions to build the t8me machine.