Most of the items I've bought on eBay over the last couple of years have been through Auction Sniper. Sometimes there was no other bidder, but it's easy to be wise in hindsight. I certainly don't begrudge Auction Sniper taking its cut. I haven't the time to watch 24/24, 365/365.
I have seen many "crazy bidding wars" while physically present in various Auction Rooms, from major international to local philatelic society. I have taken part in some myself, and asked later how I could have been so stupid, particularly after paying 50% more than I had intended.
eBay is no different! It's so easy to be carried away in the excitement of the moment - "One more bid and I'll get it!"
I hope to become an eBay seller soon, to get rid of "surplus to requirements" items and finance my "collecting" addiction. Snipers will be welcome - the more the better. I'll be setting my starting prices to break even. If I make a modest profit, so much the better.
Best wishes from Melbourne, Australia.