Here`s an idea...
Add a trade box that gives you the chance to write a little bit more about what you`re selling (for those who prefer to use area 13 for sales). For instance, you might want to sell multiple things at once, or perhaps you`d like to give the NF sailor equivalent to a 'carfacts' report. A player can view the additional data if they so choose.
No trade tax either (other than the few points).