Spare a thought for those losing money every week! Although I do sympathise with the original poster, he is obviously not careless with his money as demonstrated by his weekly profits. Sober or drunk little numbers on a computer are tough at the best of times... we've all bid on someone with the later or instant realisation, why have I done that and then hoped for 3 minutes that a previous bidder will return.
As others have said, suck it up and return stronger. $300k to you is 2 weeks profit and although that doesnt make it right its not as an expensive a lesson as it couldve been.