I normally decide a price Im willing to pay early, and bid in last few seconds.
Otherwise you tend to get shill bidders.
I had one guy I was going to buy ford capri mk1 from outside of ebay for 15k which I thought was a fair offer.
he put it on ebay, he was shill bidding and car sold for 9k which was his own high bid, I was the second highest bid at 7k when he started biding on his own car cause my auto bid was $8999.
Then contacted me and said you can have it for 15k.
I told him nope 7k or [DELETE THIS POST] off, and reported him to ebay after he told me he bid on his own car.
Australian consumer affairs got in on the act and tax department (selling as an business not paying taxes as he had a lot of other sales) which ebay reported him, not me.
2 months later a friend had the car for 6.5K at auction.