I suggested something similar in my post.
https://com.prosperousuniverse.com/t/my-opinion-on-the-current-state-of-the-game/4176
Let me quote myself:
“A feature that I personally miss is a private contract system and a barter system. I would like to see the option to post ads aimed only at specific players or members of specific corporations, so as no one else could pick these ads. I would also like to have the possibility to exchange through contract some materials for some other materials, without credits involved (barter). There should also be the option to simply donate to some other player materials or credits, without anything in exchange. As of now, players just go around these limitations and post buy orders of 100+ BSE for 1 AIC or sell orders of 1 DW for 100K AIC.”