If this is already in the enhancements or the pipeline, then I apologies that I didn't find it earlier.
It would be ideal to be able to sort the marketplace (Markets and Prices - existing offers) by other factors such as distance or time taken, so as to make a better decision who to buy from or sell to. For example, at the moment the distance is shown, but it would be great to have an option or pop-up which shows how long the delivery (of goods or gold) will take based on the sender's caravan speed, and how long your own vans will be busy doing the journey there and back.
This will open up opportunities for Alliances to form Trading Alliances, holding a warehouse and market in every nation in Illyriad and transporting goods between them to balance up resources in each nation, so that every player has a source of resources nearby. Of course there may be price differentials, which will develop naturally and without the need to introduce them artificially in game play.
In addition to this, it would be great to have the option to send my own vans or to say "buyer collects"!