Thank you for the response.
I entered in my original basis and improvements in the Total amount paid box, and on the next page added in the appropriate sales expenses.
Not having seen a 1099-S before, the thing that is had me heading in the wrong direction was one of the notes when you click on the "Total amount paid" "?" states: "Note: The cost basis on your 1099 may be $0. Or, you may have received a $0 value from your import. Keep it at $0 for now. We’ll help you adjust the value later."
Guess this just applies to other 1099s (e.g., 1099Bs), not a 1099-S.
