this is all pretty frustrating!
Owning land is not frustrating.
However, it can still be helpful to call a few large civil engineering companies in the region and briefly ask if they would develop a residential area. If yes, meet with them and have a rough cost estimate prepared. Such an offer costs nothing (unlike an appraisal) and you will have an idea of the approximate costs. Once you are there, make an appointment with the municipality and discuss the future development in a bit more detail. That also costs nothing, but you will know whether it is even a possibility. For example, if elections are coming up next year, no one wants to upset the residents and initiate major construction projects. The established residents are always afraid for their peace and idyll.
On the other hand, if the municipal coffers are empty, the chances increase, since the municipality always profits from such projects...