It's a fairly low risk, low cost approach for the person trying, though, isn't it? With potentially significant benefits.
We have no way to know in advance anything about the situation of the potential sellers. They may indeed not be interested in selling and scrap the note. Or be so affronted (why ?) as to refuse to engage.
It only takes one house where the situation is suitable to make it, IMO, worth a go.
It doesn't change anything else about the process, the price still needs to be negotiated and the potential buyer's situation discovered and evaluated.
I'd encourage anyone to give it a go. I accept that I am biased by living in a village where properties often change hands in this way. At least some of these end up in the hands of estate agents anyway as part of the negotiate.
The benefit is that it gives the potential buyer a jump on the competition. And potentially a contact within the village which can be helpful, too, to provide an in to other community related matters.
Give it a try and good luck