Having worked at a dealership bodyshop before, there is more damage $$$ wise than what they quoted you. Just a slight bump to the rearend of a car runs $1200-$1500 for labor & paint.
You hit a cow? Was it on the roadway? The reason I ask is that in the State of Texas, livestock owners are responsible for any damage caused by an animal that has gotten loose. Its not your responsibility or your insurance to pay for the damage.
Sorry that it happened, sounds like you had alot of blood & sweat put into your ride. If there is anything I can help with, just let me know.
Fortes Fortuna Avadait- Fortune Favors the Bold