Ebay auctions are not limited to the 2 bidders (you & fellow member) in your scenario. A 3rd party may bid higher still and win the chip. And who's to know what fellow members may be interested, but are waiting till the last seconds to bid. I say bid independently, and the chip will sell competitively.

In the case of the annual club auction, where virtually all bidders are fellow club members, the logical extension of going easy would be that all lots would sell at the opening bid amount, since further bids would be competing against another member. (An unrealistic scenario, I know, but just drawing out the analogy.)

And lastly, if sellers thought that they weren't getting a full competitive value for their offerings, they might be hesitant to offer nicer chips... particularly in a no-reserve format.

I'd vote for bidding the personal value you have for the chip. In the end, you'll win some & lose some.

(In reality, it's rare that I can figure out who I'm competing against on ebay, since they screen the names now. I don't worry about it.)