Indoor is not hard, you can pull 1 oz out of a 40x40 space or a spacebucket (the latter can be built for about 50$). A 60x60 tent can net me around 4oz every 3 months or so, although I grow 1 auto at a time for about 1-2 oz at a time, this is enough for me and the wife.
As for your calculations, my anecdotal experience is thus: 1g is up to 6 smokes for me, 5 g gets me 32 doses of edibles but the high is a bit more potent and lasts longer.