Convincing property owners to sell

Hello, I need your advice. We are looking for a plot of land and actually only in two towns. There are two building plots available, but my boyfriend doesn't like them. Otherwise, nothing. I have now seen a house in an absolute dream location with a large plot of land and simply called the owners to ask if they wanted to sell part of the land. Apparently, it already belongs to the daughters, but they said that Mom, who still lives in the house (she is in her mid-80s), should decide. The "problem" is that on the "part for sale" their prefabricated garage stands. The elderly lady said that she doesn't really know, she has no say in it. Only trouble, they would then need a new garage... I already said she doesn't have to worry about that... Do you have any idea how I can convince the lady to sell to us? It really is the last possible plot in the area and it would be so great if it works out. Because of Corona, I thought I would make a letter with a photo of us, where I introduce ourselves. What do you think about that and do you have any other ideas? It just has to work. Thanks and best regards Knatti

Due to Corona, I thought I would make a letter with a photo of us, where I introduce us.

Yes, that is a good idea even without Corona – especially considering the age of the addressee, it is definitely a better idea than a video.

but they said that the mother who still lives in the house (she is in her mid-80s) should decide. The "problem" is that on the "half of the property to be sold" their prefabricated garage stands.

Well, in her mid-80s, you can probably count the years she will still have a car (and incidentally also the years in which she might feel a little safer if a nice young family lives next door). I would consider the idea of leaving the garage in place; that way you already have a parking space on paper, and for her last years of driving, she can continue to use the garage.

Have you even checked if you can build there?

Thank you for the answers

so the garage would have to go and you would build a new one. That is clear. Otherwise, the plot would be too small for a building.

yes, just checked again with the city. A new building would be no problem.

Do you possibly have mutual acquaintances who could vouch for you? Otherwise, I would still develop plan B in parallel. What does your boyfriend not like about the other properties?

so the garage would have to go and you would build a new one. That would be clear. Otherwise, the plot would be too small for a construction.

How old is your garage and what does the garage look like? Could you score points with a better garage, maybe better lighting, easier access, remote opening, windows in the garage, or similar?