There is an arm mesh and a series of 1p animations and some blueprints and a few sounds as well. But those are only for the purpose of preview and reference. It’s because we think in different projects people need different arm meshes and animations according to the subject and style of the game, so it’s hardly possible to provide a common framework which can be plugged into different projects right away. So they are only provided to help users to preview the final 1p effects and functions of the weapon mesh. And they are totally free in this pack and our next series of weapon packs. 
If you are asking the price, we can not declare it before Epic formallly put the pack on to the UE4 Marketplace. But I can promise you now, the price will be acceptable by most people even students and our work worth it.
If you like our pack, vote on it at https://trello.com/c/d3TLxra3/223-military-weapon-pro-pack-m4a1
Thank you!