I'm not on fixed income per say but the mrtgage and bills get me down.
What happens though once a year - cause I'm more lazy than too busy - I get to plant seeds for things like carrotts, onions, peas. and lately I've been picking blackberries to make jams and tarts etc.
Now normally I don't think of this as cheaper food - I just get a great buzz out of eating what I or nature has produced. Everytime I harvest - I keep saying I'm going to do this proper next year - and then the too lazy/busy bug bites again and so it repeats.
But the Buzz is still there - and it's still the reason I plant and pick. But the side effect is carrott seeds cost less than a Euro a pack and easily 5 - 8 lbs of carrots grow ?
Then the taste kicks in when you eat them - try it out 53, the only investment is time - but a great hobby is achieved.