When people are trading items, base or uses?

hi everyone! i'm unfamiliar with the trading system surrounding uses, or the item itself. for example, when someone asks for healing salves, and says they will buy 2 of them for XX SC, are they talking about 2 uses of a healing salve or two healing salves? hopefully that makes sense. should i always assume people want to trade for the base item rather than just the usages?

In general in my experience people mean that's what they're paying for full use items, unless they specify that uses don't matter (e.g. for quest items, it will accept anything even if down to its last use, so it wouldn't make any difference). But for things like healing salves if they say they're looking for 2 I would definitely assume that they mean 2 full use items - so 4 uses total, if you see what I mean.