Standard income? How much is that? Law-abiding citizen? Are you serious? Was alcohol hard to get during prohibition? Is it hard to get now, with a tax? How about cigarettes. Have they disappeared yet?
Standard income is average, normal people. You can't really tax anything out of the reach of billionaires, now can you?
Alcohol during prohibition, I'm not sure what that has to do anything, except proving my point about law-abiding citizens. It sure was hard for law-abiding citizens to get... impossible actually, since you could not be a law-abiding citizen and have alcohol. That's what we'd call "Mutually Exclusive".
Alcohol and cigarettes, I know quite a few people who have stopped smoking and/or drinking because it's so expensive, and those are addictions. Far more would stop if they weren't addicts.
The NFA is a perfect example of taxing something (effectively) out of existence. It's pretty hard to argue that there wouldn't have been far more automatic weapons and silencers in private hands if there hadn't been a 2011 equivalent $3,200 tax levied. It's practically chump change today but it sure wasn't in 1934.
If they put a tax on all firearms purchased today, do you think it would be $200 or would it be the equivalent of $200 in 1934? $3,200.
How many guns would you buy if you had to pay an extra $3,200 for every single one?
I know how many I'd buy. Zero.