I am not completely sure, but I believe the buyer cannot give you negative feedback if you "win" the unpaid buyer case, where the buyer never pays. However, after you open the case, if the buyer does pay for the item within the alloted timeframe, they can still give you negative or neutral feedback (and low DSR's). If they do neg you in this case, you can still call ebay, and see if you can get this feedback removed as you can argue this was retaliation for opening the case. However, it's not guaranteed ebay will do this, esp if the feedback stated some other problem (like slow shipping). Therefore, for myself, if the buyer does not pay within the time that I specify in the listing (7 days for me), I send them another reminder message over ebay telling the customer that payment is due but asking if they need more time. If after 2-3 days, if there is still no response, then I usually open the case. Many times, immediately after you open the case, the buyer will pay for the card:
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