Most recurring manual work has never been costed, because it never appears on an invoice. Put the numbers in and find out.
What this doesn't count: the cost of mistakes, the delay while everyone waits for it, and what that person would otherwise be doing. In practice those together are usually larger than the time.
Tell us about this oneMinutes × how often × a loaded hourly cost. Loaded means salary plus employer's National Insurance, pension, holiday cover and overheads — we use 1.3× salary, which is a fair middle estimate. Divide by 1,650 productive hours a year to get the hourly figure.
The mechanical slider matters because you almost never automate a whole task. You automate the part that needs no judgement and route the exceptions to a person — which captures most of the saving and none of the risk.