Value for property that’s not currently for sale
I own a commercial building in a downtown area, and I’ve just been made aware there is a developer interested in buying part or all of my block for what sounds like a tear down/new build. I know this is likely a near-impossible question to answer, but historically, what kind of markup might I expect for an offer on a property that is not for sale? Obviously, the property is worth whatever the seller and buyer agree on. Historically, though, what could any given property owner expect at the end of negotiations? 

I have not yet been approached with any offer. I just want to be prepared if/when that happens.
[{"id": "ewu571o", "text": "Hire an appraisal to tell you the as is value and the value after the development. The developer needs a profit margin. The more precious your land the more you can get.\nIf you ask a price that deal unprofitable for the developer then it is a lose lose.", "replies": [], "depth": 1}, {"id": "ewuvajg", "text": "As a developer, this is the kind of attitude that kills deals. Not saying you shouldn't be properly compensated for your asset but the upside belongs to him because he is taking the development and construction risk. There is an agent in my market that kills more deals than he closes. He gets in an owners ear and tells them all about the development value and how their property is worth multiples of what it would be for an end user. Developers just don't buy them. Use an aggressive cap rate to come up with a valuation but don't expect to get double market value or anything.", "replies": [{"id": "ewv0xho", "text": "All of this. Had someone once demand both a slightly above market price AND an equal amount of equity in the deal. There was no possible way to underwrite that stupidity. My advice is the same as others, have a Broker give you an Opinion of Value and temper your expectations.", "replies": [{"id": "ewvgt69", "text": "My concern is being under water on the deal. I\u2019ve only had the building for a year, and have very little equity into it so far. I\u2019d also have the expenses of moving and a realtor, if I use one. I\u2019m not looking for a whole number multiple, but if I could walk away with 20-30% before expenses, I\u2019d be ok. I don\u2019t want to be greedy and I don\u2019t want to impede progress or sour the deal, but I hope to be fairly compensated. If I get lowballed vs what I owe, I can\u2019t really afford to agree to anything. To me, a fair market offer isn\u2019t quite enough for a property that\u2019s not currently on the market. \n\nI\u2019d definitely like to pay for a brokers opinion and an appraisal. I would hope to avoid a commission on the sale, though, since most of the \u201cselling\u201d part of the realtor\u2019s job was unnecessary. I would think a lawyer could handle the transaction just as well for a flat fee. \n\nAsking questions because I legitimately don\u2019t know. Like I said, I bought the building a year ago as my first, and only, commercial holding. Any other insight, whether I\u2019ve asked specifically or not, is greatly appreciated.", "replies": [{"id": "ewvu3vx", "text": "Wait until the offer is made ? They might not even move on your property,", "replies": [{"id": "ewvxfe6", "text": "Absolutely. I just want to be prepared with knowledge on how to go about things on my end IF it happens.", "replies": [], "depth": 5}], "depth": 4}, {"id": "eww7u54", "text": "This is all hypothetical at this point, but get your money (within reason). You should not feel bad turning down/countering an offer if it doesn't work for you financially. I believe everyone's point is to just enter those discussions armed with accurate information. Pay a broker for an opinion of value. It will be cheaper than an appraisal and will give you some general idea of what the property is worth today. If you closed on the property a year ago, then your basis is still pretty high, which I'm sure the developer knows.", "replies": [], "depth": 4}], "depth": 3}], "depth": 2}, {"id": "ex06hw3", "text": "To add to this, a lot of times an overreaching seller permanently misses the boat on development. If the project moves forward without their parcel and their piece is too small to be feasible for a dense development, once they opt not to sell to the developer, that ship has sailed.", "replies": [], "depth": 2}], "depth": 1}, {"id": "ewuvg33", "text": "An experienced broker can value your property. It will depend on a lot of factors like your zoning, how critical your piece is to the project, economics of what can be built there, cost of tearing down your building, any existing leases, etc", "replies": [], "depth": 1}]