I would be in tears and it would be so hard for me to begin to try to calculate compensation. I am really, so sorry for your loss. In terms of straight up money I would look at places to see how much started pullets cost, they are usually more in line of 30+ dollars, depending on breed. If they need proof to back your claims you can show them links. Check Murray, McMurray, MPC, Ideal, etc and get an idea of what it would cost to bring in birds that are near POL, from breeders or hatcheries that are established. That is all without shipping, which usually costs quite a bit too. I agree with many of the posters that they should also compensate you for the fencing or any structural damage the dogs did. Now that you know this could very well be a problem again or that some other predator may be able to wreak the same havoc I would go with the recommendation of some of the other posters and look at electric fencing for the future.
I'm so sorry, my heart aches for you. I hope we have been able to give you some guidance when I am sure your head must be spinning and your heart must be broken.