You can't sell it more than what you paid for it. That is illegal.
Seriously, it is a very limited edition team gun... Not seen any go for sale so no guides. Hmmm
Let's break it down.
New Axe = £415
Redline = £192
Barrel kit = <no price released> call it £100
To buy all this new, call it £707. Now custom marker... hmmm
Personally, i'd try it at say £600 and go from there?