I agree to adding protective clauses, but there are other aspects of the purchase we don't know from your post (like do you need financing?).
Hope this helps,
Beachfront Realty, Inc.
Richard and Glenn are right. Just also try to assess your risk tolerance for this purchase - what is your exit strategy if the building does not complete it's transformation.
Speak with Mortgage professionals at banks but also Mortgage brokers who have access to many banks (including local and regional banks,) and see who has the best plan to get you into a 50% sold building. 51% is the magic number on a building that is already built but not finished.
Call me if you need any clarification on any of the above. 646.442.7407
Buyers don't realize that they can send out time of the essence letters on purchases.