@Jason Rostar
You bought the home for 285,000 because that likely was roughly what the market value of it was at the time. Sure low appraisals happen all the time but an appraisal coming through 20% under the contracted price is definitely not common. So it is most likely that your initial offer of 350,000 was more than the home was worth.
The seller was stuck with the 280,000 appraisal for 6 months for any FHA/VA buyers because that is what the rules are for those loans. It is one of the risks that you are taking when selling to an FHA/VA buyer and why conventional loans are more attractive to sellers. Having an appraiser come before you put the property on the market is a waste of money. An experienced real estate broker is capable of determining market value.
One way to minimize the risk of getting a low appraisal is to have your broker meet the appraiser at the property when you have a contract. The broker should build a rapport with the appraiser and cover the evidence of why the property is worth the contracted price. There is NO way to 100% eliminate the risk of a low appraisal it is a one of the risks of selling real estate.
Best of luck.