He knows he won’t get more than the appraised value and probably a lot less than if you leave the place vacant, @John Roberts. You’re afraid you’ll be forced out if he sells the place.
You guys are playing a game of chicken with each other.
In fact, if you are a desirable tenant (pay your rent on time, take care of the place, don’t make the landlord crazy, etc.) why would anyone who buys the place want you out, unless they also run a restaurant and want yours? Is this likely? Would the place be easy to re-rent? Do you truly have no other alternatives if you really must move (and/or does he believe that?)
Not a lot to go on here without more info but I suspect you hold stronger cards. A signed lease from a long-term desirable tenant will maintain the value of his appraisal. Don’t forget, you’re providing the cash flow. How much is an empty restaurant worth, unless there are higher and better uses?
There doesn’t appear to be any benefit to you by signing a lease with a 60-day notice clause. It only makes it easier for him to sell, buys him time, and adds risk to your continued tenancy.
From what little you wrote, and I realize we’re talking about your livelihood, I would refuse to sign a lease with the 60-day clause and, assuming it even makes financial sense to you, offer to pay the appraised value. An agent, if he has one, would think clearer on this. You might discuss this with a knowledgeable agent yourself.
You already said he’s an accidental landlord and wants out. Now he runs from you? This is telling.