You probably know that putting contingencies in your Sales and Purchase contract throws up red flags to motivated sellers, and who wants to do that? Not me.
So how do you protect yourself without alarming the seller? You do that by adding one specific clause to your sales and purchase contact.
I always point this clause out to my seller and explain what it means. To date, I've never had a problem or had a seller want to back out. It's definitely much better to point it out than to simply ignore it and let the seller find the clause. You will have a problem if you do this.