"Hi, Regarding the Jansport rucksack, I made a mistake. I really can't afford to purchase this item. Sorry." - Now Blocked eBay User
The subtle lack of sincerity coupled with the overall disregard for my time really makes this email worth while. I get it, we all get caught up in the heat of the auction battle, God knows I have, but at least I skipped a few meals and paid for my sins. Eat well tonight, sir.