Is there a way to get a list of the original starting bids on all the auction items?

Yes, this and more data is easily available for you to sort and download. Once you’re managing the auction on the dashboard, click on Items. Then click the three horizontal lines near the top of the page to switch to Table View. 

From there, click on the bookmark icon on the far right of the page. That will allow you to toggle the fields you like to see on the table (such as Starting Bid, FMV, Donor, and so on).