Scary mary - offering on a plot of land

Yes, we have decided to offer on a plot of land we like. The vendor has already signed a contract with another buyer but, we understand, has some clause that allows them to review other offers. It all sounds rather mysterious but we hope they accept our first offer, although suspect they won't.

It is just over 3 acres, although I am convinced that the measure of an acre here is smaller than in the UK, so it looks like 2 acres to me!

Picture included below