I switched Maddie to a raw diet a few months ago, and I've found it to be very cost effective, and easy to do. Not to mention, she absolutely LOVES it. No wasted food ever. Here's what I do:
A couple of times a month, I buy ground meat on sale (usually turkey, because she likes turkey a lot, but other meats as well as frozen liver slices), and a big package of chicken on sale, usually chicken legs, sometimes thighs. I separate the chicken into packets of 3-4 pieces, freeze most, keep one in the fridge, along with one of the ground meat packages.
Once or twice a week, I make 'dog veggies', which is assorted veggies, a handful of frozen berries, a couple of eggs (with shells), some oil (usually olive), garlic, turmeric, and brewers yeast. I just put it all in the blender, and whirl it, then put it in a tupperware in the fridge, next to the ground meat and the chicken pieces. (edit: the reason I make the blenderized veggies is that I was spending a lot of time mincing stuff, and she would even then sometimes just eat all the meat and maybe 3/4 of the veggies. The blended mix is easy to stir into the ground meat, and she can't avoid her veggies that way
Here's the feeding schedule:
Morning: Portion of ground meat (about 1/4 lb for Maddie, ymmv), with a couple of tablespoons of 'dog veggies' stirred in. Put bowl on floor, watch food vanish.
Evening: A piece of raw chicken, given to her in the back yard. Stand at window, watch food vanish.
Occasionally, I'll mix it up and give her a piece of liver (chopped, in a bowl) for dinner. That's always a hit. Treats are rare, and are usually little bits of whatever I'm eating, sometimes she can have the 'cookies' offered everywhere I take her in my dog-friendly city..
Provide lots of fresh, clean water, and watch the dog thrive.
And that's it! I've found it to be very cost effective (considering I was buying very high quality prepared food...which she sometimes would eat, sometimes refuse...now we never have that issue). It's also not really that time consuming. With 3 dogs, you'd have to buy slightly higher bulk amounts, but seriously - you might consider giving it a try.