The potion of forgetfulness should cost 250 dram, but it shouldn’t be a potion we get… instead it should be a rare, one of a kind, ingredient that only that vendor has. The ingredient would be perishable (5 mins) so to discourage re-sale. And for 500 dram you can buy the recipe. Of course you’d only need the recipe once and then have to forage for the rest of the items needed.
The items needed would be based on the “strength” of potion you need. The strength is based on your level. Because higher level means more respec power needed.
Example:
Need to respec the first 2 of the 4 tiers of talents.
Queens ear, green, roto spore and sunfish, red, reed flute and blue moon spore, green, “rare ingredient”, blue, dip bottle and finish, then age potion. = potion of forgetfulness.
Need to respec all 4 talents.
same as above, but add 3 more steps and harder to find ingredients.
My 2¢