Then you aren't destined to have that item, and you go buy it from someone who does. That's the market for you. If everyone can supply, there is no demand.
Destiny? Are you kidding me?
This is not a lottery, this is businness and cannot rely on just fate by design. It's just broken this way.
Would you accept to get to the last boss on an OP or HM FP and have a chance roll to find the door open or closed and actually be able to play it? This is exactly the same.