Silly question, but do you have time to make your own yogurt? I personally never did, but have read it’s pretty simple. Just an example of saving money by being creative, even with food. You can get your kids involved, if you have school aged children, especially now in the summer.
Very often making food such as dips for Shabbos by yourself is cheaper than ready bought. It’s also good to be aware that groceries/supermarkets sell a lot of products that are really luxuries. Just avoid those except for rare occasions. Hatzlacha!