The thing you don't realize when you buy bids is... it gets down to the last seconds on an item and then you bid... the time goes back up. Don't count on being able to hit it quickly at the end of the time limit. You can spend all your bids on an item very quickly as the price escalates 10 cents at a time.
I think some people get good deals by chance on here, but you have to be really lucky. I am not willing to waste my time on luck.