Thomas
I think the correlation between your maker preferences and their inability to fill an order for you is one that may not be overcome in a timely fashion. Knife makers utilizing high end steels, and unique design, are smaller by nature of exclusivity, and cannot keep up with customer demand as is. ie. Spartan. Survive!
As a veteran, I respect your commitment to this cause, heaven knows there are a lot of down and out Vets, but you may be forced to broaden your search by lowering the exclusivity.
As far as dollar amount raised, what you lose in higher priced percentage you could easily make up in volume with a lesser priced, popular design. For this, the aforementioned ESEE Izula II is a wildly popular knife, I have one myself, and would also open your perspective buyer window.
To be honest here, I'd love to buy one of these knives simply to support the cause, but $250-$300 just isn't something I can part with easily for wall hanger. Admittedly, that's just me, because I personally don't have a need for a knife based on Randall King's Desert Enforcer beyond collecting. Now, for 25% above retail (that may not be how you're pricing but I'm making a point) on a limited Izula II, I wouldn't blink, and maybe even order several extra for gifts.
Just another mans thoughts on it all, probably worth what you paid for it.
Regards
Craig