Recently I have been quoted $1,200 - $1,500 for ON with time ranges between 6 pm - 9 am and another 8 pm - 6 am
I think it all depends on what you agree with the companion and whether they meet your needs or definition of BF experience. I think I would pay $2,000 if i liked the provider and we agreed what what was covered during the ON. In my opinion you pay for the company and if I really want to spend time with a specific provider then it's up to me if I want agree to the cost.
Perhaps it's me but I hate to negotiate so I don't try to push for discounts; if I want to meet someone and I know their rate I can decide if it's worth it to me to pay the fee.