This time of year veggies are pretty cheap and will fill a good portion of your plate! Granted, organic anything is costly! There are some great sites with recipies for healthy eating on a budget google them. For snacks, keep fruit ready to go, sliced veggies with hummus, and one of my favorite snacks is to take turkey pepperoni, place one layer on a cookie sheet and bake at 375 until they curl up and crisp. ( watch them- there is a small window before the burn!) Maybe 10-15 minutes. But watch them! Once they look brown and crispy, set them on a paper towel and let them air dry. They will taste like exrta crisp bacon. Popcorn is another cheap alternative for snacking, but it must be without the oil and butter! Either microwave lite of investing in an air popper.

If you have an Aldis in your area you can get some really good deals. I don't have one near me anymore. Miss those cheap prices. Eggs seem to be cheap right now. And you can always get BLSL chicken breasts near me for about $1.88 pound. And for some reason I can get pork loin for $1.77 per pound at least once a month. We live on that. You can do quite a bit with a pork loin.

for the losing weight part, splurge and get a kitchen scale for about $20 and learn to log calories very accurately.
This will help you figure out how many calories you are eating
You have to eat and for losing weight it doesn't matter much what you eat as how many calories you eat vs burn.
You can look for alternatives like tuna in water or mustard instead of mayo or vinegar instead of salad dressing.

For me, so I could eat enough quantity without going over the calories, I've cut out most bread, potato, rice, dressings, mayo and eating a lot more tomato, onion, garlic, eggs, fish, and shrimp.