You come up with a price (value of your company). The buyer comes up with a value. If you can't decide on one or the other, get a third party, and the one tha

You come up with a price (value of your company). The buyer comes up with a value. If you can't decide on one or the other, get a third party, and the one that is closest to the third party wins. Works well, it's in the best interest of both parties to not under or over-value the company. Negotiators are a good thing to have.