Ideas we had is put a gold cap based on Craft poisonmaking ranks or caster level. Or to limit it to a certain dosage amount when casting it based on caster level
Any feedback would be good if i can't work something out i might just change disciplines
Your DM could require an XP cost based on the poison's value. Psionic powers tend to use an XP cost to balance them out when necessary anyway. For example- 1XP for every 5gp of value. This would deter characters (especially lower level ones) from freely mass producing poison. He could also require particularly hefty DC skill checks for creating such poisons so that it will be nearly impossible for lower level characters to create the especially powerful poisons altogether.
Unless the DM also rules that Psionic Minor Creation creates
permanent items, an XP cost would be disproportionate to the benefit gain.