question about autoflowering plants

Hey all. I'm planning a small grow room that still a ways away. Anyway I had an idea and I want to know if it will work/how well it will work.

So I'm planning on getting a 250w hps, possibly a 400w hps as my main light ( probably have a few CFLs around the plants too )

anyway if I bred my own autoflowering seeds, could I just keep say a couple plants in the grow room constantly and then replace them with fresh seedlings after harvest? Would this be enough to sustain one persons stash?