Please respect sellers. Meaning if someone is selling an item, don't chime in with random comments about how their item sucks, or is overpriced, etc. If the item really is overvalued, etc, then the marketplace will correct that (ie. he won't be able to find a buyer). This does not mean you cannot bargain, by all means bargain for what you want, but this is different from trying to ruin a person's for sale thread.