Simplest way is to look up the Notice of Trustee sale and take the amount due on the loan (balance due) and substract it from the opening bid. The difference is their expenses.
If you are asking that they give you an itemized list of their costs of doing business…forget it…would you?
Where I live the Bank’s calculation of it’s foreclosure bid is public record. I would think that would be common to most States, but can’t say for sure.