Hi
How are you doing?
I'm great. Are you ready to go camping?
Yes I am ready. But I am low on some item and I don't mind trading with you. Do you?
No that sounds good. What are your preferences?
I am so low on Food and I have two kids with me. The highest amount of item I have is Firewood. Do you mind taking some in exchange for Food?
That matches up well with my needs. How about you take all the food and I'll take all the firewood. or we can go 2 & 1 if that better suits your needs
Thanks for making this easy for me. I don't want you also to run low on supplies so soon. I will give you two firewood while I take 1 and half food. How about that?
That would be great but I don't think they let us break bundles in half. How does this sound... You get 2 food, 1 water and 1 firewood. I get 1 food, 2 water and 2 firewood. Sound 
You should understand that water is also essential for the kids. Likewise firewood to keep them warm. What about 2 foods for me, 2 firewood for you. And we all are happy and enjoy our camping?
here's what I propose to get a deal, you get, 2 food, 2 water, and one firewood. I get 1 food, one water and two firewood
I think that is okay by me. I don't want to stress the conversation. You have been helpful enough.