Do you know why the majority of conservative politicians havent brought up the cost? Because its so relatively negligible its not even worth ranting about. Plus, it would leave them open to the counter point that this could save money.
Who do you think pays for the emergency room costs when people get shot? Who do you think pays the police who have to respond to such incidents? Who do you think for the paramedics who respond to the incidents? Who do you think pays for the state and federal workers who have to compile the stats on such cases? Who do you think pays for the storage of the weapons that were used after an incident? Who do you think pays for the added police security after such a incident? Who do you think pays for the new training those officers have to undergo? Who do you think pays for the lawsuits that inevitably crop up? Who do you think pays for the lawyers who have to fight against those lawsuits? I could go on, but you see what im getting at.
The United States Government has a vested interest in keeping its citizens safe. You could say thats number 1 on their job description. And, like most expenses, prevention can be cheaper then fixing the problem after its occured.
Plus, if your arguing against improved background checks, your arguing against this guy:
Finally, as a side note, no one cares about the size of government. Republicans learned that in the most brutal way possible last November. No one really cares how big or small the government is(especially since the GOP absolutely believes in Big Government as long as its about sex, marriage, bailouts, defense spending, etc), people only care about how good the government is.