Okay, let’s tackle this. So Charlie has 31 years of experience in a specific niche (telephone systems). The industry average for customer system engineers in the US is around $50–$100 per hour, depending on the location and industry demand. Considering Charlie’s experience and the fact that he worked for Lucent Technologies, a well-established company, I’ll estimate his rate to be on the lower side of the average. Maybe around $75 per hour, considering he’s not a senior-level engineer and is based in Detroit, which has a lower cost of living compared to other major US cities.