when you use exogenous hormones you shut down your own bodies production and replace it with what you are putting in.
200mgs on average would put your T levels around 800-900 area. so really it wouldn't be much of a difference if any. the big misconception is that people think if their T levels are 900 vs. 450 like your case that you would get twice the results.. that is bullshit. plenty of guys take gear and still look like shit.
bottom line if you want to use steroids that is fine, but you might as well run a moderate dosage. so aim for 400-500mg a week