Question about A BEST

[JEWELian]

Yeah, the slipcase with 6xdifferent covers is first press. (much like A BALLADS which had the slipcase with 1 cover with 4 different covers on the actual booklet, MY STORY which had 4 different first press covers, MY STORY Classical and the ayu-mi-x 6 which all came with first press slipcases, too).
So no, you won't be able to buy it from CDJapan, YesAsia, HMV, etc.