There are quite a few frugal cookbooks out that have recipes for hearty cooking.
I’ve fed myself for $25 a week (excluding shabbos). Not that this is healthy or balanced, but I’ve purchased day-to-day cheap bags of produce for $1, rice, beans, potatoes, eggs, onions, 50 cent yogurt, and soup powder. In NYC, they also sell $2.19 big loaves of rye bread, OK-Pas Yisroel! (May be Stern’s, but I see it sold in ShopRite and Russian stores).
Also, this is l’toelet harabbim- ShopRite in Brooklyn has Manischewitz Matzos, KOSHER FOR PASSOVER, as well as Yehuda matzos, KOSHER FOR PASSOVER, on sale for 99 cents. I purchased some already for Pesach.