I disagree. Even though this start with missing information, something could be done here.
Although I understand the thought behind @lubos decision not to estimate cost of stock items, I can also relate to @BawarYassin’s issue with this. Both are valid points.
A similar thread has already been in ideas but I’m hesitant to put this in ideas because I’m not sure whether this is to be handled by another idea, if that makes any sense.
More specifically this:

Fair enough, let us say it is a mistake on my side and Manager has no shortcomings. How can I find these errors to fix them if Manager sweeps them under the rug I have more than 850 inventory items?
And this:
Now, I’m not saying your complaint is invalid. I just don’t agree with your solution and believe there must be another way that will work for both of us. That is reports could be more accurate (your request) but the program should continue “scream, shout and kick around” (my request).
So, in case the cost estimates aren’t going to be provided by Manager, a flag needs to be raised and the user should be able to see the accounting effect for the transactions in order to understand how to correct them.
But we will have to see what @lubos thinks of this.