Sorry for the bump but there ARE icons for stat reset potions in Media.pk2. Not sure when they will be implemented though.
Here's the icon:
There are entries in itemdata.txt for the level ranges 1~40, 41~50, 51~60, etc. so I would assume the higher level you are the more expensive it gets to completely change your build.
Also in an unrelated note there are also entries in itemdata.txt for 8-week, 12-week, and 16-week gold and silver tickets.