This past year the NERB was a few dollars shy of $2,000. It's very likely they raised it again but I doubt it's too much higher.
You don't need to shell anything extra out for endo, prosth, or the diagnostic exam.
For the patient part, it is a nice gesture to pay your assistant, your two operative patients, and your perio patient (or one patient x2 or x3 if you use that patient for two or three parts). In other words, at $100 per person, you should be shelling out $100 for your assistant and $300 for your patient(s). You should also have a backup pool of patients in case the examiners strike down a lesion. We had enough patients on reserve for half of us, so that was an extra $50 per person. Then we each chipped in for the couple faculty advisers for their help... just got them a nice gift.
All together it came out to about $2,500. We got to take out a loan to cover the exam cost ($1,985).