Firstly , I want to sell this staff

Would I get more money from selling the staff as a whole or salvaging it and getting the +29 staff head?
Also, I want to upgrade this bow with a +21 bow grip :

Which would benefit me more? the +5 armor or the +21 grip?
Lastly , according to this web site defense bow grips only go to +4 armor , is this upgrade a rare , or is the site outdated?