Here is a fairly robust set of brackets for how much to charge clients at each strategist level:
Junior Strategists £150 – 200 per day
Middleweight Strategists £200 – 300 per day
Senior Strategists £300 – 500 per day
Strategy Director £500 – 750 per day
Facilitators £600 – 1000 per day
Source: Major Players Salary Survey [ but check out our freelance rate calculator here – link ]
The earning potential for the best strategists is great but remember that the annual equivalents of these numbers are immense – it is unlikely you will be employed for the entire year so enjoy it but be clever not only in work but in how you manage your finances.