lsommerer, that spreadsheet is awesome! I haven't gotten that advanced in my auction spreadsheet, mostly due to rudimentary Excel skills! I noticed that the drop down boxes truncate the player lists past 120 or so, how do you work around that?
The tracking of budgets has been the biggest problem at our auctions. One way we get around it is that people aren't required to fill their roster completely if they spend their money. After the auction we hold a waiver wire draft where the people who didn't budget wisely pick up players at a free agent salary of $5 to fill out their roster. I have also had people continue bidding even though there roster was full which can screw things up, too. The important thing is to take your time as commish even if people are screaming about how slow the process is to make sure you are accurately recording the information, especially if you don't have an auctioneer.
The spreadsheet is a very big asset to have. At a minimum you can use it to keep track of the bids. Also with technology being what it is, the spreadsheet can be projected for all in attendence to follow along or shared over the internet using Windows Messenger if anyone needs to participate from a remote location (the fewer remote participants, the better though!
We found the open bidding to be too chaotic without an auctioneer, so we conduct our auction "poker style" where we rotate nominations and bidding in a preset order. If you pass on a bid once, you are not allowed to re-enter the bidding porcess.