so gta 5 is 60 gigs and i copied the gta files off of my brothers pc to my hard drive. the thing is he bought gta on steam and i have all those steam dlls and stuff i want to buy gta todat but the steam version in g2a is just too expensive my parents don't want to but that for me just wondering if i could play the game without downloading all of it with the files i already have if i buy a rockstar global cd- key