On items like this I keep checking to see if it gets resisted. Sometimes it is a non paying bidder, sometimes a bidder who demands a full refund for some real or imagined reason and sometimes it is a shill bidder. When every I see the second bidder has a very low number of feedbacks or worse none at all I approach with caution. Don’t let a shill bidder run the price up. Set your limits and walk away above that. There will always be another one along soon enough.