The CPCs are estimates, not actual data (that why you see the word “Estimated” used in the column heading). This is what is known as a data outlier. You should anticipate them and generally not consider them as valid data. Don’t get hung up on outliers, they aren’t significant except to signify anomalies for further study. Having said that, it is an interesting anomaly.
I see a couple of flaws in your formula for calculating potential earnings. Why would you use Global Search data when your website will generally not likely rank and draw traffic from all regions and in all languages? Especially not in competitive keywords.
Also, there are wide variances in typical CTRs especially when you have a keyword-based on a large company name which is also identical to the domain name. The official website will typically get 90%+ CTR in such cases. You need to use different criteria for different types of keywords. There is no credible one-size-fits-all formula for calculating potential earning that doesn’t make allowances for different types of keywords.
