Email the seller and ask to cancel your bid or go to Customer Support tab and follow the prompts to cancel your bid. They will notify the seller. I wouldnt mention that reason. Keep in mind that if the other item started later, it could also get bid up so you wont gain anything unless these items are Fixed Price.
You can't undo a bid.
you can hope someone else bids higher. or when notified that you won the auction you decline the item at that point.
nope
