data

Is anyone aware of a module that would allow creation of widgets with multiple sub-fields?

Say you have a custom XML feed that contains a set of main records, e.g. store name. Then say each store can have an optional set of special offers, which has half a dozen fields (title, price, etc) - rather than setting up yet another content type and doing a messy add/remove for nodes and node references each time, it'd be much cleaner if I could just use one field with nested data. Are there any modules with a nifty UI for doing this, or do I ultimately need to create a some widgets to do it?