Running CT v2.2.4 at the moment and having troubles adding columns to the fieldtype.
The docs show an inventory column, but I can't see how to add that. Docs are spotty at best. http://cartthrob.com/docs/fieldtypes/price_modifiers_configurator/index.html
When I click the add column, it adds the column to top portion of field, and I can type in it, then on entry save, column is lost.