To add to what's already been said, you have to pay attention to the wording in the sales thread. Some sales state "First I'll take it" gets the item. That usually means the first poster gets the knife, Some sales state that the seller "reserves the right to sell to whomever he wishes", the first post doesn't necessarily get the item. Some sellers will look at a potential buyers activity here before making a decision on whom to sell to. Some sales threads state " paying members only".
Having a paying membership and contributing to the community(outside of the sales forums) helps establish trust within the community.
Having a paying membership and contributing to the community(outside of the sales forums) helps establish trust within the community.