Unlike some other shoemakers I have yet to see a shoe from Edward Green where the quality has been anything less than one would expect when buying it from Edward Green whether it's from Ralph Lauren, Brooks Brothers, or anyone else.Whereas you can get something of lesser quality when buying an Alfred Sargent from J Crew. But then again you'll notice your paying a bit less when buying it from J Crew. Bottom line: if it has the Edward Green name on it is at the level one would expect from Edward Green.
However if your able to find this boot elsewhere you may fair a bit better price wise as Brooks Brothers does not always have the best pricing for Edward Green shoes or boots. I'm not that familiar with this model so I sorry that I can't assist you with locating it elsewhere.
Just because it is listed as an E width does not indicate that it is a normal US E width that you may think it is. In fact this probably equates more to a US D width as the E is considered more of a standard width for Edward Green. In fact I'm not even sure if Edward Green offers a C width, but I know they do offer a D width however. Keep in mind that the Last will also determine what width you might want to go with as well. The D width on the 82 Last in fact can be rather narrow where other Lasts are not so narrow.
It's always best to try it on before you buy it. However you can always order one from Brooks Brothers and return it if it doesn't fit.