Even a manual buy order does not accomplish this. In the end I only want our regions to be able to freely sell to mine. It is not about getting too much food but about not losing money to outsiders. We are strapped for cash as a rule and while I am glad to give it to our nobles in exchange for food I do not want a single coin leaving the realm unless I specifically choose to have that happen. If I set a manual buy offer for 1000 then ANY caravan from any place can stop buy and take our gold. Sure I get food but that is not what I want. I want food from internal regions and I want them to get my gold.
not if you are really micro-ing the thing and set it to go live when the caravan arrives only. thing about trade offers listed in the caravan page.. is that the ones listed, i think, is either the auto or manual offers only (don't know which one). so in essence, it would be a bit of a guess work as to when your markets will be opened.
furthermore, if you are desperate not to let others sell to you, then make prices sky high and you send out caravans to buy. ie... others can buy the food that is earmarked for you, but only at a premium. really clunky and problem with having to send caravans out early to make sure they are heading back filled once harvest is in..
my problem with auto trading (or manual trading) is that it's in general geared towards food producers sending caravans out to sell to food consumers