A. H. Hirsch Special Reserve Straight Bourbon Whiskey is the famous and generally well-regarded bourbon made at the distillery in Schaefferstown, Pennsylvania, that was best known by the name Michter's.
The last company to market that whiskey was Preiss Imports. Preiss Imports has also put out several products under the name Hirsch Selections, including this one. I'd be reluctant to spend $400 on any product that I don't know anything about. All I know about the various Hirsch Selections bottlings is that they are not the same whiskey as the A. H. Hirsch Special Reserve.
All you have to go on is the reputation of Preiss Imports and that's positive, because they have a very good reputation.
Maybe you realize this now, but you should never assume that price = quality, not with bourbon, not with anything. With bourbon, you also should never assume that older automatically means better. There's also the matter of personal taste. Some people love a lot of wood flavor in their whiskey, some don't. If you buy the most expensive thing in the store believing it will be the best thing in the store, you're just setting yourself up for disappointment.
As for evaporation, whiskey in the barrel starts to evaporate on day one. That's part of the aging process. Often with very old whiskeys the barrel will be half empty, maybe more, when it is harvested. Sometimes it all evaporates and the barrel yields nothing. That's why very old whiskey is so expensive. You're paying for all of the whiskey the angels drank.
In the bottle, there shouldn't be any evaporation if there's an adequate seal. Screw tops are better than corks but a cork can keep a good seal and it's easy enough to check by seeing where the fill line is.