It's very easy to make your own egg food at home without added vitamins.
Simply hard boil an egg, mash it up and serve at room temperature.
You can add finely chopped vegetables if you wish.
If you make a "batch" of egg food, you can freeze it in ice cube trays and when frozen, empty the trays out into a plastic bag. That way you simply thaw one cube before serving.
Serving egg food once or twice a week to adult budgies is just fine, however, when they come into condition, it is best to eliminate the extra protein from their diet at that time as a part of the steps to discourage breeding.