First off, yes, this is different than LuigiHann's poll. And second, no, I'm not going to start charging $3 for my songs.
Now that that's out of the way, the question stands: Would you be willing to pay $3 for the right song? And if so, what exactly makes that specific song the "right song" that you would be willing to pay $3 for it?
I'll start! Yes, I would. And the song is - Dream Theater, "Metropolis pt. 1". Partly because it's 9:30 in length, but mostly because it's the first song of theirs I ever heard, and the one that made me a DT fan.