They did an Elseworlds back in 2003 that had the destitute Batman scenario - "The Golden Streets of Gotham". It was a period piece set in the early 1900s, but still pretty interesting.
As for other poor heroes, I would list DC's Ragman and Marvel's D-man (both of whom have literally been homeless and living on the street).
As for other poor heroes, I would list DC's Ragman and Marvel's D-man (both of whom have literally been homeless and living on the street).