On Marketplace.tf for $2.25.

Have 100 dollars.

Can buy roughly 44 keys, will sell each and gain $2.05 each.

That will result in $90.00

Weapons wanted (In order of priority):
Preferably most expensive to least expensive.

Rifles
Pistols
Submachine Guns
Shotguns
LMG

AK-47 | Case Hardened (Minimal Wear) -            $30       30/90
M4A4 | Asiimov (Well-Worn) -                      $30       60/90
AWP | Redline (Field-Tested) -                    $10       70/90
FAMAS | Sergeant (Minimal Wear) -                 $1        71/90
GALIL | Orange DDPAT (Field-Tested) -             $2        73/90
P2000 | Pulse (Factory New) -                     ALREADY GOT IT
Glock-18 | Dragon Tatoo (Factory New) -           $2.80     76/90
SSG 08 | Abyss (Factory New) -                    $0.75     76.75/90
P250 | Supernova (Factory New) -                  $0.90     77.65/90
Five-SeveN | Urban Hazard (Factory New) -         $0.30     77.95/90
Tec-9 | Isaac (Factory New) -                     $1.00     78.95/90
Mac-10 | Heat (Factory New) -                     $1.30     80.25/90
MP9 | Deadly Poison (Factory New) -               $0.35     80.60/90
PP-Bizon | Osiris (Factory New) -                 $0.80     81.40/90
P90 | Module (Factory New) -                      $0.25     81.65/90
MP7 | Ocean Foam (Factory New) -                  $0.60     82.25/90
Mag-7 | Memento (Factory New) -                   $0.50     82.75/90
Nova | Ghost Camo (Factory New) -        	  $0.30     83.05/90
Sawed-Off | Serenity (Factory New) -              $1.30     84.35/90
XM1014 | Quicksilver (Factory New) -              $0.15     84.50/90
M249 | System Lock (Factory New) -                $0.30     84.80/90
Negev | Desert Strike (Factory New) -             $0.10     84.90/90
Desert Eagle | Conspiracy (Factory New) -         $4.25     89.15/90