There is never[*] any point in placing a bid on an eBay item before the final seconds of that auction - otherwise you give other people (whether the seller themself - where it's called shill bidding, and is illegal - or another user) an opportunity to decide to outbid you.
The three basic rules for placing a bid on eBay are:
- Bid once, and once only, on any auction
- Bid the maximum you would be happy to pay
- Bid as late as possible
[*] If you understand the concept of BIN Stomping, then you know enough to devise your own bidding strategy.