Any negative meaning of the words "What is the damage"?
Solution 1:
If used when buying something, "What is the damage?" simply means "What is the cost?" In this case, 'damage' implies that the cost is 'damaging' the speaker's finances.
This is usually used in a casual, friendly way.
As with anything, the speaker's tone or the context of the situation may show that the speaker is upset, but the words themselves don't imply that.