There is the legality and the practicality:
A verbal agreement is completely legal
and binding. The problem is if there is a later disagreement, how to prove it. It's your word vs thiers unless you have witnesses.
In this case, there is an email
trail which makes it a written contract
, so all the discussion about verbal contracts is irrelevant. You don't need signatures to make a legally binding contract
. If they (or in this case thier agent) sent you an email
stating that the offer is accepted if you agree to X, Y & Z and you send an email back agreeing to X, Y & Z, you have a legally binding contract.
There is still another practicality issue. You would probably win if you took the owner to court but it's likely not worth the trouble and even if you intimidated him into taking your offer, you could expect him to be difficult thru the entire sales process. Better to walk away.
PS: As others have mentioned, make sure any offer is contingent upon a full survey
. That way if something bad turns up, you can get out of the deal.