If you had free shipping you would get TON of credits bid, but since you're new, people don't trust sending money for shipping, not knowing for sure that you'll actually mail what you advertise. You won't get any of the Listia credits until the buyer acknowledges that they received the item, but if they give you money, there's no way to get it back if you don't follow through-- and a lot of people are on Listia to get things they do not have cash for so they can't afford to take chances with what they do have. Once you have a solid reputation here, people will trust sending money for shipping, but until then, you're not going to get nearly as many bids as this is worth. BUT...I am watching and may bid.
You can't do that. Once there are any bids, you cannot delete the auction or make any changes. If you had a minimum amount you were willing to accept, you should have started the bidding at that amount.