August is a very long time to wait.
I dunno, I guess there are plenty of reef tank out there that don't have low-iron glass and you don't really hear all that often "Man! This tank sucks because it has regular glass instead of Starphire!!" .. so it's probably OK.
Having said that I'd still check into the cost. If it was say a difference of $100 for example, and if you had some means to make up for that (I dunno, ride your bike to work for a month instead of drive? Don't go out for dinner or lunches for a couple weeks if you do that sort of thing? Etc.? Etc.?)... but otherwise, I don't generally condone going against the wishes of SheWhoMustBeObeyed..
(Having said that, I find it's better to ask for forgiveness than to ask for permission. It's always a fine line!!)