[vicky_molokh]

So, simplifying and streamlining some of your words, we can get something along the lines of:
For each full-time (~8h/workday, on average), moderately competent agent (i.e. neither a superspy nor some comedic clueless tool) eats up 1 Average Income of budget. Otherwise, every reasonably loyal member (neither fanatic nor a half-hearted participant) contributes roughly 10 man-hours per work week (assuming 5/7 workdays and ¼ of 8 available hours per day). This is without travel, i.e. assuming an agent either contributes near one's residence, or makes shady contributions at the day job (e.g. a forensic quietly analysing an extra sample on the behalf of the conspirators, or a politician voting for a law that is in the conspiracy's interests); the on-the-day-job contributions can take up less time, OTOH they are risky, and might require finishing the actual job in free time, thus generalizing shady contributions to the same 10 man-hours per work week seems reasonable.