Sometimes I want to sell an item but ask for payment in different resources e.g. selling 1000 marble, asking for 10 coins plus 100 water.
Or someone might be selling a friary for 9,000 coins, but I only have 8,000 coins and 200 map fragments.
Could the trade system by expanded to allow multiple resources to be offered? At present, the solutions all require trust and honesty, for instance buying the example friary for 8,000 coins, then buying a fish for 200 map fragments. If one of the parties decides to rip off the other party by only accepting one of the two trades, there is no recourse.
Being able to offer 1000 marble + 1000 water, requesting 10 coins + 50 gold bars as payment would solve all these issues.