Survey: What Minimum % of Pre-Acquisition Cashflow Should You Retain

Something I've not seen talked about much, and I would like to get everyone's opinion and what they aim for.

What is the minimum amount (in terms of percentage %) of pre-acquisition cash flow you require after everyone is paid, including employees, debt payments, investor payments, seller financing, etc...?

In other words, how much is left over for you, after everyone else is paid? In percentage terms?