Actually, in my opinion money system in deathmatch is ok, true. But in BR when the opposite team wins, and I - for example - kill two players (which, when sum up, causes situation when in my team everyone's dead and in the other one only one player is alive), i still spawn with 20$*. Kinda sad, when you kill and there is in fact virtually no reward.
*Maybe it's true when you kill only players from the bottom list, true. But still