Nothing unusual about this. Unfortunately, people, for whatever reason, will want to buy or possess something and out of impulse they will "buy it!!". Explains why a lot of us are in credit card debt. Anyway, it is not uncommon, as another example, for people to bid on your auction and not come through if they win. Apparently, they think they win the item as a prize if they're the high bidder. It's the same with buying - the desire is strong but the money is not there.
If someone should offer me what I'm asking asking with no questions asked or without a lower offer, I would either suspect that either (a) my asking price is too low, (b) they're just kicking tires or (c) they actually want it. If they don't come through, so what. From where I sit, there a plenty of decent folks on this site - one potential buyer who didn't come through shouldn't worry you.
If someone should offer me what I'm asking asking with no questions asked or without a lower offer, I would either suspect that either (a) my asking price is too low, (b) they're just kicking tires or (c) they actually want it. If they don't come through, so what. From where I sit, there a plenty of decent folks on this site - one potential buyer who didn't come through shouldn't worry you.