Maybe make convoy cost 3 then. IIRC we discussed the trade token cards and they all more or less make sense without the Trade token effects at their costs.
It's been a while since I changed it, but I think the biggest reason Convoy costs $4 right now is that Enterprise has too many $3 cards and needs more $4 cards. If Trade Goods ends up testing well, then I replace Craftsman with that, so that's just replacing one $4 card with another.
I'm thinking of changing (and renaming) Domain. People complain that the VP is too swingy and luck-based. The concept is a card that you want several of, but can only get from other players. The original version was a Treasure that gained you a Gold if you lined them up, but that was too many hoops to jump though. Steal one, then collide them before they got stolen back? Not happening in most games. Then there was a similar version that let you search your discard pile and get the bonus if you revealed one. That was super wordy and not that compelling. The VP was a good way to make you want Domains in your deck, but not have to collide them.
But now I'm thinking, maybe it's good enough to just make you want to gain Domains, not necessarily make you want to have multiple. It should work out mostly the same.
Domain: Treasure, $3
Worth $1. When you gain this, gain a Gold.
I will probably also change Barrister. Right now I've replaced the Thieves in my main set with Bandits, which is basically Barrister without the Domains. With this new version of "Domain", I may try to create a cheaper version of Barrister, probably one that trashes Domains from others' hands.
Barrister: Action-Attack, $4
+$2. Each other player trashes a Domain from his hand (or reveals a hand without Domains). Gain a Domain from the trash.