Suggestion Why not negotiate?

I like the idea

Before giving their items, there should be an agreement so they will recieve the item at the same time.

I second this. And you can only trade items that are of the same value. If you're trading a 500 cheese hat, you can only get an item that costs 500 cheese. This is so noobs don't trade 1 cheese for the 4001 helmet. Forgive me if someone already said this because I stopped reading after this post *_*

I thought it was a pretty good idea. It's sort of like in China where you can negotiate a price and the seller can determine weither or not they want to sell it for that price or not.