kcscrapper 
Never, ever escalate a case if you are the seller, unless you are 100% positive you will win. Most of the time it is better to let the case run out. If they don't pay within 4 days of opening a non paying bidder case, you can close it manually.
The only time I would escalate is if the tracking shows delivered and the buyer opens a case for item not received. Even then I would call instead of going through the ebay resolution center.
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