Comment by iy56

It just means they feel like the other party is forgetting about the cost. For example, if I hear my friend raving about this new phone that only costs 99 dollars, I might remind him that it would require him to upgrade to a data plan that costs 20 dollars more per month. That doesn't mean that the phone isn't still worth buying, just that it's not as cheap as I think he is imagining it to be.