From what i have seen (And from experience) It is usually mainstream weapons that are easy to scrap bank. These include weapons such as: Degreaser/Cow mangler/B.A.S.E Jumper/Rocket,Sticky Jumper/Machina/Scottish resistance/Crusaders Crossbow. Of course, reskins such as the fortified compound are going to be easier to sell than the Huntsman, but again, this only applys if the buyer needs the weapon quickly or if they are collecting.