Say I want to sell common stock that I own, to someone who meets the SEC accredited investor definition. It seems that right of first refusal means that the company could buy the stock instead, but it would have to be at the price that I set with the external investor. In that case, don't I as an employee get liquidity either way, since it's being bought at the agreed upon price?
Correct. The problem is a lot of companies go further. They restrict sales completely. In practice, insiders are allowed to purchase at depressed prices in tenders from time to time and then resell at a mark-up in the open markets.
(In the options exercise agreement): "All certificates evidencing shares purchased under this agreement shall bear the following legend: "The shares represented hereby may not be sold, assigned, ..., except in compliance with the terms of a written agreement between the company and the registered holder...""
(On the share certificate): "This certificate and the shares represented hereby are issued and shall be held subject to all ... bylaws of the corporation, to all of which each holder ... agrees to be bound"
Either of which seems to give the company the ability to unilaterally reject any transfer/sale of shares.
In my opinion selling within the existing pool shouldn't be restricted, but this could become a sticky issue around board control so that probably contributes to the desire to control/curtail it.