Buy all items from the Survival Air Support Armoury.
Note: You do not have to buy all the items from this Armory all in one Survival match. Purchasing these items are cumulative across all games you play, so just remember which one's you've bought. This Armory comes available at wave 4.
Below is a guide to this Armory and what costs and levels things are:
Air Support Armory:
■Perk Care Package
■Quickdraw: Level 0 & Costs $3,000
■Steady Aim: Level 8 & Costs $3,000
■Stalker: Level 22 & Costs $4,000
■Extreme Conditioning: Level 36 & Costs $4,000
■Sleight of Hand: Level 50 & Costs Costs $5,000
■Predator Missile: Level 0 & Costs $2,500
■Airstrike: Level 4 & Costs $2,500
■Delta Squad: Level 14 & Costs $3,000
■Riot Shield Squad: Level 21 & Costs $5,000