I think a way to improve the trading of Battle Dex is to limit people to 2-4 trades a day.
I used to put 5+ trades a day and i was constantly pushing other peoples trades down,and i felt kinda bad...so here is a solution, feel free to disagree and tell me why u agree or disagree

-Random

and add the AND OR feature >.>

The wha..?

trading Recon Hero for Fighter Hero OR Infantry Hero, for example

oh thats a great idea !

been waitin several months for it. Would help cut down on the trade spamming

What I would really like to see was something like this for every player, maybe besides the current market:
A "shop":
You put in all cards you want to sell, you can either do this for something or just make it "await offer".
When you think somebody has a good offer for one of the things you offer, you can accept it.
If everybody has this people will click through these "shops" (maybe accessible via player profile), can search for shops which have a certain card available and when the game grows bigger maybe have an option "only show trades that you can accept right away".
I hope you got what I meant
The normal thing could then be limited to 3 posts a day, people will make cheap offers there, linking to their shops.
Also maybe ebay style auctons? Need bigger community for that tho.