Goodwill Industries has a nation-wide auction site.  Click on
categories, then on musical instruments: http://www.shopgoodwill.com/ 

When you scroll to the bottom of any page you can click on "search"
and type in piano roll.  Always put your search in singular, not with
an 's' on the end.

Last week they had a large collection of rolls that brought only $10
plus shipping.  Several weeks ago they had a music box with 6 melodies
that brought a little over $100.  It's a fun place to shop.

Al Good
Waynesboro, Pennsylvania