Buying property tips?

The wife and I have been looking for a piece of land on the island to build our retirement home, found a piece of property (5 acres) that we're interested in. I have never bought property, wondering if anyone could share some pointers/things to consider. It's an owner contract (they're loaded, were going to build there for daughter, she was supposed to build but did not). There's already a well (capped, we're requesting re-test) and it's cleared, no easements, been perked for 3 bedroom, have perk test filed with county). Any thoughts would be appreciated!!