5 Mistakes in Real Estate Wholesaling You Should Avoid Mistake #1: Not Understanding Your Market. Mistake #2: Not Understanding Your Buyers. Mistake #3: Poor End-to-End Due Diligence. Mistake #4: Complacency When It Comes to Your Buyer(s) Mistake #5: Getting Too Reliant Upon One Contractor in Fix & Flip. Mar 11, 2019