That already exists.A user created a new listing with Type "For Sale" and it should be "Wanted". I see no way to edit the listing and change the TYPE. Not sure if this can be resolved with the enhancements add-on.
But it will only let you edit to a type that is valid in the category the ad has been posted. So if you keep For Sale and Wanted in separate categories, you'll first need to move the advert, then the relevant type will appear when you edit
(This is the edit page)