I will give you all the food and 1 water for the firewood.
Oh, I am not comfortable with that. The weather is colder than expected and having a family of 7 leads to higher consumption of firewood.
That is my main concern also. What is your biggest need? 
High need for firewood
hmm, that is also what I need. What kind of compromise were you thinking? 🙂
I can offer 1 package of firewood, 1 package of water and 2 food going by family's consumption volume
How about 1 firewood and 2 water and 1 food? That gives you more of what you need most but at least I can keep my kid and dogs hydrated well. 
ok
Great, I am glad we came to an agreement
Nice negotiating with you