Again, here is a scenario.

Current bid - $10.00 at 12:00 noon
I Bid - $100, Current bid shows $10.50 at 12:10
You bid - $15.00, current bid shows $15.50 at 12:20
You bid - $20.00, current bid shows $20.50 at 12:30
You bid - $30.00, current bid shows $31.00 at 12:40

At this point the bidding history would show:
My bid (at $100) at 12:10
Your bid (at $30) at 12:40
Your bid (at $20) at 12:30
Your bid (at $15) at 12:20
Previous bidder (at $10) at 12:00