You obviously have no idea how these things work.
The employees would not be selling appreciated stock back to DOLV, they would be selling them on the open market to schmucks like us. DOLV would have no liability whatsoever to buy stock back at higher prices.
When you but a stock (ANY stock, not just DOLV) on the open market, the money does not go to the company, it goes (via the brokers involved and the stock clearing system) to the seller of those shares (the previous owner). When you sell, you are getting money from the new buyer, not the company.
This is stock markets 101.