Metro: Last Light - Businessman

Make 100 Purchases.

Simply make 100 purchases and this trophy is yours. If you use the trick during the Bandit Chapter to keep selling guns you can also buy a grenade, sell it, back out of the menu and then repeat the procedure for an easier way to unlock the trophy. See the Walking Bank trophy for more info on the Bandit Chapter trick.

An alternate method is to buy a Throwing Knife as they only cost 1 MGR each. Hold the Joypad correctly then you can alternately and quickly press X and SQUARE with your Middle and Index fingers until the trophy pops (which should take about 30secs if you press the buttons fast enough).