As in title, in the quest "Not enough panties" once I get past the camgirl scene with Ashelin she tells me to pay her with dark eco. I checked around and apparently you have to go to the store and are given a chance to buy it but you have to pay in panties (hermione is supposed to help with that). Problem is, no option to buy Dark Eco ever appears
I tried skipping days, doing quests in different orders etc. but it just always gets stuck on this stage.