Hi PowerPuff,
No, No, No, never make a serious bid early; the system is far to open to abuse; make a nominal tactical bid by all means, but otherwise always save your big gun strategy for a last moment snipe; that's the only way to protect yourself from the unscrupulous shill-bidding vendors (and other naive nibble-bidding buyers). If you are a keen eBayer, as I am, and you don't have the time to snipe manually, get a sniping program.