I hope this is the right place but I have perhaps a small suggestion.
Is is possible in the Sales/Trade topics that everyone who opens a topic adds their continent in front of the topic title? Like:
[EU] Ponies for sale!
[US] Ponies for Trade!
With UK, AUS, etc. Something I would like to buy some ponies but then I figure out the person is from the US which cranks up the shipping cost a lot (and don't question the import fees *shudders*. With this it's easier to see from where someone is shipping from. The downside could be that people can ignore your topic beforehand... I would like to hear everyone's opinion about this.