Rich is relative. If one earns 1,000,000 per year and one spends a million per year then one is benefiting from a high standard of living. If one earns a million per year and saves more than half, then he (she) is wealthy (by monetary standards). One can be relatively rich on a modest income if one is able to manage money. I consider myself to be "comfortable" but not rich. My net worth is enhanced by land but occasionally I invest in liquid assets. Someday I will be "timber rich."
As far as the riddle goes, I am uncertain of the answer.