As a guy who sold his last business to the first offer (which was a good one, but not a great one), I would encourage you to think VERY hard about what happens after the sale. Are they hiring you? If so, how are you going to like that? I hated it.

If they're NOT going to hire you, what are you going to do next? It doesn't sound like you'll have enough money to retire, which means you get a job or start something new.

You have an incredibly unique opportunity RIGHT NOW. Many entrepreneurs try multiple times and NEVER make something people want-- you may never do it again (there's a helluva lot of luck involved).

So, if I were you, I'd keep growing it unless you think it's a short term play or that it's going to quickly plateau.

Even if you ARE going to accept the offer, COUNTER. Say, "We think we're worth a lot more than that-- we'd like to see a better offer."