I haven’t sold a watch at auction, but have entered other items. Can be months before the auction takes place, the gamble of if it will sell, commission fees and cataloging and photographing fees etc and waiting for the payout.
Before going down the auction route what about a direct sale to a dealer, or entering the watches for sale on commission (Subdial, WF etc).
If you are looking to reduce numbers and it’s not purely a financial driven thing, you could consider part exchanging against something else. This is usually the easier option and dealers are more likely to play ball as they don’t have to part with cash.
I sold 13 Orient Makos on e-bay during Jan/Feb this year, I think I only got my money back on one watch, the rest had differing degrees of loss, although they all did sell in the end.