How long does it take to do manually, once?
How many times will it need to be done?
What is the price of the person who will do it manually?
What percent of the time, when doing it manually, will a mistake occur?
How long does it take to correct a mistake?
Total Manual Cost:
What is the price of the person who can automate it?
How long will it take to automate it? (Including testing)
Total Automation Cost:
It will cost you less to automate than you will spend doing it manually.