Hey there friend.
Hello! How are you?
I am fine. I am settling down in preparation for camping.
Awesome!  Do you go camping often?
No. This is my first time and I am anxious whether I have enough supplies. 
I understand that.  I camp quite often, so I can help you with any questions you have. Let's try to come up with a fair deal for the extra packages we can have.  I often get chilly due to some medications I take, so I would really like to have extra firewood.  Is there anything in particular you would prefer to have extra of?
Firewood is also of priority for me. I am  afraid I will be a Popsicle if I do  not get more wood for the overnight fire. 
I can certainly understand that, no one likes to be too cold.  How about I'll make an offer, and then we can see where we stand in terms of what we think is fair.   What if I take 2 packages of the firewood and you take 1.  That way you can be sure to stay warm, and I won't need to worry for my health. In exchange for this you can have 2 of the food and 2 of the water and I will take one of each.  You'll end up with more extra supplies, than I will, but my health is my biggest priority here.
That sounds like a good deal to me
Great!