You can't raise the calcium levels of flies by adding calcium to the media, they are exceedingly efficient in excreting any surplus calcium so the flies still have a negative calcium to phosphorus ratio. This requires that the flies have to still be dusted.

If you want to look at inexpensive medias check out the recipes here http://doylesdartden.com/fruitfly.html#MEDIA as some of them cost just cents per culture.

What is required to produce a nutritious fly is much better known now than in the past but is a little too much to sit down and type out here, but your recipe just isn't it...