I bought a telescope for $60, an hour later they emailed me and cancelled the order because they discovered the price was a mistake.
They should be able to get away with the cancellation. Does not appear that the time was sufficient to bind the seller.
Yes, if the price was a mistake the retailer can almost certainly cancel the order. This is especially so if they realized the mistake in a short time period before you relied to your detriment on receiving the product at the advertised price. You did not suffer any adverse consequences from this mistake---other than not getting the bargain you hoped for. It would be different if they shipped the telescope to you, you began to use it for a while, and then they tried to bill you more for it----they couldn't do this. But they are permitted to cancel the order in a situation like this.