You are purchasing a used se-tenent set of 4, #1928-31 American Architecture stamps, 18 cent, off paper.  The scan is a sample.   The stamps include: NYU Library, by Sanford White, Biltmore House, by Richard Morris Hunt, Palace of the Arts, by Bernard Maybeck and National Farmer's Bank, by Louis Sullivan.  Shipping is $.68 within the United States, outside the United States is $1.55.  I do combine items to save on shipping costs, I only make adjustments for weight changes so you can sometimes put several together and it has no impact on shipping costs.  Thanks!