I remember in early 70s as a kid , there were no supermarkets, and fruit and veg in shops was only what was in season. 
sounds dumb.. but if its too dear, dont buy it... 

also we butchered our own meat and ate cuts that pets used to turn noses up at years later. 
or go vegetarian.. 

Pulses like lentils and beans cheap esp if dried and soak 

sprouts are very healthy and can grow them in moisture in bathroom lol 

if you don't need to be up to date on events can get free newspapers from newsagents, saves them throwing them out.

bread is cheap 

so is junk food unfortunately lol 

can always get on food delivery list from Vinnies? 
oh, um old recipes from The Great Depression like mock chicken lol