I usually get so many lvl 1 and lvl 2 potions that I will use during item use, but if they are getting close to running out of time in my stash I will just sell them for gold. I think it would be great if potions sold would go to the next level like catalyst. For instance when selling lvl. 2 potion there could be a flask that fills up as it accumulates portions of potion until lvl. 3 is reached. Don't know if this has been brought up before, but it would be nice to obtain instead of the miniscule amount of gold you receive.