I ran into a couple situations where the buyers asked me a ton of questions and claim that he wanted to set up a ETA to finalize the deal. Only to have the 'potental buyer' backing off a few hours from the meet. Also I was given explanations such as 'suspecting' what I have to sell is of questionable quality, another time a buyer simply told me he's too busy with work to make the meet at all.
I guess this is part of what a seller have to deal with ...likewise any on of us can walk into a department store or say a car dealer saying I would like to buy the product. However nothing is final until you sign on the doted line or have the cash up front to make that an offical transaction.
I think it is normal for a seller to experience the ups and down,the biggest reward is when you make a successful transaction and receiving a positive feed back from the buyer.