While this shouldn't be a complex question - it seems to be.
Example 1 (yes, we need examples)
Rolling fee - $25 is our fee. This is the fee the site charges to take your prints
DOJ Fee - $32 - if there is a check in that box (look three quarters of the way down on the right side of your form)
FBI Fee - $19 - if there is a check in that box (look three quarters of the way down on the right side next to the DOJ box)
Now - the complex part:
Example 2 - You have a billing number (look in the applicant section - right side - third line). Then you may only have to pay the rolling fee. I say may, because there is a chance that the Requesting Agency is only exempt from the DOJ fee and is also asking for an FBI check. You may have to pay the FBI fee and that may or may not be at a reduced rate.
Total: $25 - $44
Example 3 - You are going to work for a company that has a billing agreement with our company.
Total: $0 - that's right - the company pays the whole thing!