To that end, what do you think a Lady Gaga CD will go for in (roughly) 2070, do you think? More importantly, how widely do you think her songs would be played by then? Would anyone still alive then even know or care who she was? That my friend is the big metric of success or failure concerning creative works.
You're assuming that a CD will go for anything in 2070. Current trends seem to suggest that the future price of music is 0$.
1.79 x 10^12 furlongs per fortnight -- it's not just a good idea, it's the law!