Bird Dog's Hungry Feral Cats

My name is Bird Dog. I have a one man instrument repair shop in Chuluota, Fl. a small town outside of Orlando. I make sure the feral cat colonies in the area of the building my store is in are kept fed (we are in a rural area, and there are many places around the building for them to reside in) ... I started doing this several years ago because I realized that when hungry, they would wander blocks at a time in search of food and they were being killed on the local roads way too often.  The number of cats I care for is between 25 and 30... unfortunately, people will drop off unwanted cats so the numbers vary. Also, as I said, I lose some due to autos. I feed them dry food and it averages about 3 to 4 large 15 pound bags a week, at 10 to 13 dollars a bag.  Any help I could get financially would be greatly appreciated. The picture is of the Southern colony... there's two others.  It's a tough life for a feral cat... eating once a day makes it a little easier. If they could, I know they would thank you, as I do.