As I read the original post, a few thoughts come to my mind.
Break down if possible and order a case of ammo for each. Usually cheaper to buy in bulk, and you will have it on hand.
I would be upset, being the guy who dropped $2k worth of business with this store, only to find out the clerk is blabbing to people about my purchases. I would not give this guy my business. Who knows what he tells others about your buying habits. "Who needs to buy 2 boxes of 5.56mm and 2 boxes of 308 every week!" "Guy must be one of those survival nuts!"
There has been a HUGE rush on guns and ammo since Nov 4th. I went to a gun show yesterday and words can not describe it. Two day show, was sold out of all "assault type " guns and case lots of ammo withing two hours!. Fire marshal cited the convention center for being way over their limit of people within the facility.
I give my face to face business to gun shops who are friendly, priced competitively, and who know the value of discretion. I have purchased a fair amount of ammo via the internet. I try not to do large orders all at one time. Don't want the local UPS guy talking about the "nut" who he delivered 10 cases of ammo to yesterday, and by the way, here is his address...
Five years ago, $2k worth of 5.56mm ammo was a LOT of ammo. At today's prices, it really isn't that much!