i got my sage naruto out of free draws, after 4 months i was level 60. If you are lucky like i was there's no reason for you to spend scrolls. Anyways, if you ONLY use free draws, is almost sure you don't get dupes, so you get all the 3, as Zelgadis said, within 1 year (just to confirm that, i can tell you I got Ao last week, after 8 months of free draws).