Watch Insurance?

I'm wondering whether you seasoned watch collectors have your watches separately insured (i.e., via a jewelry rider separate from your home owner's/renter's policy)?  If so, how did you prove the value of your watches for insurance purposes? 

I now have over 100 vintage Bulovas/Accutrons and am wondering if there is a way around having them separately appraised, as I suspect that would be very costly (?).  Most of them were purchased on eBay, and I did not keep records of the purchase.

Thanks in advance for any experience/advice you have to offer.