What is your Retirement Cash Flow Number?

[Mike Roy]

Hello BP - I've been thinking quite a bit about the amount of monthly cash flow I'll need to quit the rat race and provide a comfortable life for my family.  Here's very broadly what I'm thinking:

Gross Monthly Cash Flow - $10,000

After Tax Cash Flow - $8,500

Housing Allowance - $2,000

Health Insurance - $1,000

Regular Expenses - $3,000

Cushion for personal emergencies, rental catastrophes or reinvestment - $2,500

So far, our 13 units brings us about 1/3 of the way there.  I'm sure we could live on much less, but who wants to "retire" early and just get by? 

What is your Retirement Cash Flow Number, and who has already pulled the trigger?  What have been the biggest surprises or challenges?