Valuation of farmland for development into building land

Stubborn. You can really make money, but you just let others do it.

Yes, I can be that sometimes. But actually I am one who can also just leave it be. It's not that I don't wish him the business, but my piece has to be tasty.

but my cake has to be delicious.

According to your idea, however, you are getting a complete Michelin-star pastry shop. And for the buyer, you are showing rotting fish for months.

Think about my potential calculation.

By the way, the purchase price can also be linked with a promissory note exploiting the property or land value increases. Get some advice.

Everyone nowadays wants to get the best financial outcome for themselves... no matter where. Therefore, your desire to earn as much as possible from the sale is not objectionable. The investor will also not do the whole project for fun but plan with the aim of achieving the highest possible financial profit. And again... in the end, it does not matter whether you feel disadvantaged afterward or not. There are only two possibilities: 1. You agree. You get amount X and both parties are satisfied with it. 2. You do not agree, as the investor offers at most amount X so that the project is profitable. But you want amount Y because otherwise you are dissatisfied. Result: You get no money. The investor cannot build. You just have to ask yourself what you want to do with the land and whether you will even get such an opportunity again. As said, no one is forcing you to sell.

There are only two possibilities

has already suggested that there are other possibilities. I recently bought farmland from someone who was also afraid that I might later sell the land as building land for a lot of money. We agreed (roughly) that he would receive half of the profit if I resold the land within ten years. With a bit of imagination, certainly more options can be found; when drafting the contract, one is largely free. However, in my opinion, one should be careful not to attach conditions "for eternity" to such a sale.

And he then sells the property for at least €380/m². It’s clear that I want a cut of that too.
If you see, land on the right and left is sold for €300-600/m². So it’s not outrageous to put €280/m² into the discussion.

I agree with you there. But if he doesn’t have the property, I don’t believe he would get a building permit. He can’t just build around my property. Then he wouldn’t get a permit.

but my cake must be tasty.

But you’re not the one investing anything.
You only have something. Development costs should not be underestimated. In the end, you’re just selling farmland that you can’t really do anything with.

Raw material is always quite cheap – it’s the “refinement” that makes flour into a tasty cake. Flour itself isn’t appealing to anyone. You can’t provide sugar!

He can't just build around my property. Then he wouldn't get a permit.

If you really have such a great "blocked property," you can anger the other potential buyers so much with your blockade attitude that you can only go get bread with presidential security ;-)