I feed my family of 4 on $700 a month. I cannot afford much organic on that budget. I buy as much as I can from amazon's "subscribe and save" and costco. I shop at Trader Joe's, Sprouts, and Whole Foods (only a few items there as they are so expensive.) If you live somewhere with inexpensive local organic farms, that would be a good idea. Can you start your own garden? I know you said vegan, but if you had your own chickens would you eat their eggs? (That's what we do.) I grow micro-greens for our hens which saves money and I think we get more eggs. I also give them organic corn and soy free commercial feed that I buy via a local co-op.
Created an instant family (7/89 and 5/91) in 1997. Made a baby boy 12/05 adopted a baby girl 8/08. Ask me about tandem adoptive nursing and living as gluten, dairy, and cane sugar free vegetarians. Homeschooling and loving it.