Hmmm an idea I can think of. much like the linkpearl one (actually uses this) in Forza 2 (Race game) you can select say the linkpearl, this would open up a kind of mini menu listing all the item you currently are bidding on as well the time left for each.

A way that could be used to help notify the player of activity on the items they have a bid on, have the pearl (much like with missions) light up a different color. or even same color.

This is just an idea I could think of, hopefully it serves some support to help build the auction system of the OP