1. shadow bows are old skin and never were very popular
2. the are considered "horn" bows, which have "built in sundering" so most people prefer to use vampiric or such on them as the sundering doesn't stack..
try to get as much as you can, which if someone will pay much more go for it, but really it could be a hard sell getting much more than 30k imo
rare skin thread says 30-50k, probably the high end because of the sundering imo
Have seen a few people who've been paying alot for these, so maybe ~70kish with some luck