Kristen Is Planning to Add New Mulch to All the Landscaping

Essay

Kristen is planning to add new mulch to all the landscaping beds around her house. She has determined the quantity of mulch she will need and identified these two options for getting the mulch to her house:
1. Kristen can have all the mulch delivered to her yard in one dump truck for $450.
2. Kristen can make four trips to the garden center with her pickup truck and haul it herself. It will cost her $75 per load for the mulch, plus $25 in fuel and truck wear per load. She estimates it will take about five hours to haul and unload all four loads.
What is the full cost of each method? Which method is cheaper? How is opportunity cost relevant?