a construction manager just starting in private practice needs a van to carry crew and equipment. she can lease a used van for $3,596 per year, paid at the beginning of each year, in which case maintenance is provied. alternatively, she can buy a used van for $5,721 and pay for maintenance herself. she expects to keep the van for three years at which time she could sell it for $1,052. what is the most she should pay for uniform annual maintenance to make it worthwhile to buy the van instead of leasing it, if her marr is 20%?