Yep. Just do Testingcheatsenabled True, then in Buy/Build Mode, Ctrl+Shift click the nectar shelf. Set to Make Buyable. Then select Treasure Content as Nectar - Cheap/Medium/Expensive or Necteaux Amazing Nectar. If you are not satisfied with the price and type of nectar available, set the nectar shelf to Normal, then Make Buyable again. A new nectar will be available.
This method applies to so many other things in Tomb Building, btw.