Quality layers, on average, need between 100g and 120g of a nutritionally complete feed daily. (about 1/4# ea).
The first thing you can do to save costs is stop feeding organic. HUGE cost savings right there.
Scraps don't really count, and won't make a big dent in the chicken's feed bill, unless you have a very small number of chickens and generate a lot of scrap in your household (in which case, cutting that waste may help your budget more). Thay are also a potential source of dietary imbalance.
Where are you located? Feed alternatives are regional.
also, I'm uncertain what you mean by "an enclosed area to free range." The value of forage is dependent upon time on ground, area of the grounds, and variety/composition of the ground. Giving a few birds free access to a couple hundred sq feet of grass just isn't that helpful. Giving them access to the same sq footage of sunflower seeds in season may well be harmful. There's a lot of possibility and not much specificity in the terms you used.