Well, imo woodcutting yews(level 60, 445gp each) makes money way
faster...
Unless you're willing to grind mining all the way to 85 then you
can mine runite(16000gp each)..which is actually what i'm doing
right now.
Then definitely mining > woodcutting.
We've got a guide here
you might wanna see. might help you with the gold needed for the
rune pick. 