Annual maintenance costs for a particular section of highway pavement are $2,000. The placement of a new surface would reduce the annual maintenance cost to $500 per year for the first five years and to $1,000 per year for the next five years. The annual maintenance after ten years would again be $2,000. If maintenance costs were the only savings, what is the maximum investment at the current time that can be justified for the new surface, with interest at 4%