Honestly, you are asking an opinion question. I believe what you are really trying to do is validate some sort of contingency you need to make, is that correct? I will tell you this, in this market here in Tucson, AZ any contingency will lessen your chance of the transaction. For example, as the listing agent when I present an offer, even for full price and it is contingent on the buyers selling their house in X first, the sellers most of the time will not even consider it. Why would they? Then need to sell, not lock up their house, no more showings or interest until this other buyer may or may not sell their house. < contingencies you are asking for, greater the chances of your offer being accepted.
Best of luck.