Sorry, when I looked yesterday morning SG Ammo had it for $250/case, with $25 shipping, so $275 all in. I just checked and they are out of stock as of right now. Here's the link, and you can click on "Notify when back in stock".
They do have Magtech and PMC Bronze in stock for $260/case, and I've shot both of those brands with no issues.
Target Sports USA has Remington UMC for $270/case (I've found it to be dirty, but shoots okay) and Armscor for $280/case. They have free shipping on case quantities.