Laid off, presented with a golden opportunity

I was laid off and as I was making my clients aware, one suggested that I start my own company and he would work with me directly.

The engagement would be a 1-year fixed fee + expenses reimbursed engagement. The fees exceed my current salary by 2.5X and seems like a no brainer but before I commit to doing this, I want to "run the numbers".

Can you let me know what I need to consider? From limited research my understanding in how to get my "income" is its going to be

Fees
Less Expenses...

Laid off, presented with a golden opportunity

from Laid off, presented with a golden opportunity