The land next to us

We are @ the end of street, overlooking a river. There is a vacant land next to our property.

My LG just finds out who owns it. Our lawyer says that the owners, sisters, have not paid any tax on it. My LG worries that sisters will sell it to a developer and build some thing on the land which is very difficult and costly or putting up a cell tower and  he wants to buy the land.

Lawyer says keep it quite and do not get the sisters' interests to sell the land. B/c once they get our bid for the land , they may be interested to get higher bidder from others too.

What do experts think?