Okay, the author has a point. While it doesn't take much effort to find a decent wool suit going for $800 (Lord & Taylor), it takes a fancier store to find prices higher than that. The Macy's on-line ad I looked at had nothing for more than $650. I don't think many of us really NEED anything better than the best carried by Macy's or L&T, but maybe I'm naive.
On the OTHER hand, in 1911, you'd get a suit from a taylor, not a department store. The suit would REALLY be fitted for you. It might be more appropriate to compare the 1911 suits to the high end shops that I skipped.
Unfortunately, the "one ounce of gold still buys a fine suit" story has to be taken with a grain of salt. While the spirit of it is definitely true, the literalness of it can never be proven. 1911 suits aren't made in 2012. (Ironically, 1911 handguns still are!) What's definitely true, though, is that there ain't no way you're getting a suit today with a $20 bill. A cheap tie to go WITH your multi-hundred-dollar suit, maybe...
http://www.shopstyle.com/browse/mens-suits/Lord-and-Taylor-US
