Steven,
I followed your steps...
Run a Mass Change.
Change: Cost
To: Cover Price
Apply to ALL Titles
You will get a warning that this change can not be undone.
Did I mention you should only do this to a Copy of your database?
After the change (done on the copy, correct...?)
Run a Collection Report.
The last page will get you the Total Cost (which is identical to Cover Price at this point).
After running the Collection Report, the Cost amount total was the exact same on my Copy database as the Cost amount total on my original database, exactly the same. Weird, so I manually checked and sure enough, on my Copy database all of the Cost and Cover prices matched, so that was fine. So I then ran Collection Statistics under File on my Copy database and there the Cost amount total changed and is now showing the actual Cover price total. Perfect!
Your steps worked perfectly and I obtained the information I was looking for. Not sure why the Collection Report and the Collection Statistics are not identical though. Thanks again.