One thing that could be done for charms is character-binding on charm trophying. The MOs already do some work on the gear but it is a bit sad to have the entire market flooded with full charm packs the moment people are quitting the game, if you don't have as much time early in the season to keep up the pace.
May also make people think twice about spending a lot of tg early, since selling your gear after you're done with the season early easily gets you the tg back. I know I've done it the last time I played.