I say, anywhere from $39.99 to $29.99, $24.99, $19.99. / $14.99 seems to cheap, if it's new locations with 20 hours or so of fresh gameplay.A really big dlc for around $15 would be nice. If cd project red ever requires you to pay for dlc you can expect to get your moneys worth.
It has to be really good quality that lives up to the rest of the games quality tho. CDPR knows what's worth what, but as of now... I just want to play the wild hunt, I hope it's fun!