Parker & Stone, Incorporated, is looking at setting up a new manufacturing plant in South Park to produce garden tools. The company bought some land $8$ years ago for $$5$ million in anticipation of using it as a warehouse and distribution site, but the company has since decided to rent these facilities from a competitor instead. If the land were sold today, the company would net $$9\mathrm{.}6$ million. The company wants to build its new manufacturing plant on this land; the plant will cost $$16\mathrm{.}2$ million to build, and the site requires $$960,000$ worth of grading before it is suitable for construction.

Which of these cash flow items is considered a 'sunk cost', and therefore should not be included in a capital budgeting decision?