I dunno, i appreciate being able to gloss over certain mundane actions with the shared understandings of common actions. Shopping, for instance, takes loads more time when everyone's in storyteller mode, and you never really know how many more sessions you've got before a scheduling error comes up. Best to keep the routine parts brief.
Schmoozing a merchant for a better deal is best handled with a persuasion check, assuming getting a good deal isnt an important part of the campaign.