50% does sound fair to you and to her. I also suggest pulling down the ammo and recovering the components as suggested. The ammo being dubious to sell and perhaps even illegal, it would be a nice gesture on her part to throw that in for free since you'll be buying the gear and not using the ammo. Just a thought.
"Always place your clothes and weapons where you can find them in the dark"
"Understand that the enemy is not the enemy in his own eyes ;this may offer you an opportunity to make him your friend. If not, you can kill him without hate, and quickly."