Ask HN: How Much Money is Enough... What's your Number?

It would be interesting to hear your specific financial goals, such as: "I would sell my startup if the net proceeds of the sale would exceed n." I'm more interested, however, in knowing what factors you considered to come up with your number.

I am asking because I run a profitable internet business that has doubled each of the last three years; our metrics indicate that we can maintain that growth rate for the foreseeable future. As with any business, there are major risks but the likelihood of them actually threatening us is relatively low; unfortunately, precisely quantifying the risks is impossible.

Since a significant chunk of my net worth is tied up in the business, I worry that a "rogue wave" could endanger our prospects. We have been approached multiple times by serious acquirers offering favorable terms and a 5x revenue multiple; so far, have I rejected their offers. We have no outside investors so the decision to sell would be entirely mine.

Since the M&A market is beginning to show signs of life again, I am considering a sale. The question is, how does one decide when to step off the train, and take a huge amount of risk off of the table? Thanks!