For the following problem
******************
Land is bought for $45000 with buying expenses of $2180, and interest rate is 9% p.a. The land is kept for 4 years with annual costs of $500, and sold for $105000 at the end of the 4th year (selling expenses are $5000).
***********************
I assume that the the cash flow time line is
-45000,-500,-500,-500,99500
Since I assume the annual costs come at the end of each year.