[Unrea1]

public OnPlayerPickUpPickup(playerid, pickupid)
{
if(pickupid == Ropa) {
SendClientMessage(playerid, -1, "ЎAquн puedes comprar ropa!"); }

else if(pickupid == Armadura) { SetPlayerArmour(playerid, 100);
SendClientMessage(playerid, -1, "ЎAhora tienes armadura completa!"); }

return 1;
}

Te recomiendo utilizar el switch.