I decided to share my spinach with my budgies, Stormy and Skylar thinking they wouldn't eat it and what do you know, I go up to my room to get my phone charger and they are eating the spinach bell pepper salad together!
I only got pictures of Skylar though because Stormy is afraid of my phone and flew off.
I'm thinking I should put a feeder in the other cage on the side the cages are close to see if that does the trick for getting the older two to eat new things.
I only give it to them once or once every two weeks for an hour should they want it because it is when I usually buy it. I don't go out and make special trips to buy them it or anything either. It's one of my favorite foods for whatever reason.