They are worthless. I'll do your friend a favor and take them off her hands for free.
Barefoot is going to be dependant on the type of barefoot as there are several versions at different price points. From what I typically see they go for about $150-$200 less than purchase price new for just the saddle. So a $800 saddle I usually see listed $600-650 and that usually is not including the pad.
I would assume torsion would be similar mark-down though they are a higher priced saddle. So if one is $1300 new I would look at $1100 or so.
With the pads you might want to price a bit higher.