With "WANTED" being the key word. I see guns for sale all the time where someone wants so much they can retire on the single sale. The bad news is "it ain't happenin'". That box will just sit on the shelf for a good, long time.
Go to gun shows and buy your ammo there. Most private vendors would blush asking half as much for the box they have. A big part of this hobby is knowing a bargain when you see it. The other part is having the $$ to take advantage of the bargains when you see them.
I got real stupid about a year and a half ago. I just started "investing" in ammo when I saw it way too cheap. That pretty much coincided with the copper price hikes.
A while back I started a thread on a gunshow. Charlie Sherrill came up with his son and one of his friends. Jr. hiked the show at a mad run, afraid he'd miss something. Charlie came to our tables and sat down for a chat. He commented later that we had a nice talk, except when I got a whiff of some ammo cheap. I'd be gone for about 5 minutes, then come dragging it back.
Charlie isn't anybody's dummy. He knows what ammo costs and understands the reasons for keeping a minor stockpile. Read his current post about his minor ammo buy. Something about thousands of rounds? OK, that was 357s, but the same theory holds.
Buy when you see it cheap. Then you won't have to pay some opportunists prices.