very hard to sell, secondary smelters are really trying to avoid it.
We had 23 000 lbs of #2 copper refused at the smelter after they found $60 worth of be-cu in the load. The whole shipment was returned.
If you have small quantities, you can try to blend it with regular #2 copper at the scrap yard. Most guys at the scales don't know how to identify be-cu.
For big quantities, it's a problem...
A chinese buyer once offered me 1.20 for be-cu. I don't know if it's a good price indicator or not.
edit : $1.20 USD / Lb