Feeding teens on a budget

Let's face it. Feeding a family on a budget when children are young is a lot easier than feeding a family full of teenagers on a budget. When my kids were young we spent $200-$250 a month and ate great. Of course I have been very lucky to only have one child with a food sensitivity and I understand diet restrictions can really put a strain on your budget.
In my home, we have 9 people. That includes, 4 teenagers, 2 preteens, a grandmother, mom and dad. It can be quite a challenge to feed everyone healthy food and not blow our budget out of the water.
When my kids were little, they ate like little people. They would also go through stages where they didn't want to eat much. Now if they say they aren't hungry, don't get your hopes up. This does not mean you will save some money. What this means is they will become hungry at a later time in the day and then they are REALLY hungry because they skipped a snack or a meal. Then they will try and eat you out of house and home. Some of my kids still think they should be offered several snacks a day and they don't actually mean snack as in here have some carrot sticks or a banana, they want a full meal.
So what does a mom on a budget do? Well, I am always looking for ideas because honestly, I am still learning. But, here are some things I do in my home.
Our budget has recently increased from $500 to $700. This amount is alot to me and has given me more wiggle room but I still have to be careful
I shop at Costco, Aldi, regular grocery stores, farm stands/stores when they are open.
I make most things by scratch including most meals, pancake mix and pancake syrup ( you can control the sweetener that goes into it), baked goods, granola, and snack foods like hummus and granola bars
We rarely buy prepackaged foods
We eat several vegetarian dishes each week
I make school lunches and my husband's work lunch
We eat leftovers
We drink water
I freeze and dehydrate produce when it is in season and cheap
I grow a garden and have recently expanded it
We rarely eat out
We go to church potlucks (I only have to make a dessert or side dish to share :D

We have an 80/20 rule. That means, we eat 80% decently healthy and the other 20% is the maybe not so healthy food the kids are allowed to have so they don't revolt. I have tried to go full, 100% healthy but in our house it is impossible. I can't monitor what my kids eat 24/7. I have also learned, they are more likely to eat the healthy stuff if I throw in a treat now and again. So, we compromise.