請教XIABATU等專家: I-485 pending for over 2.5 years.

Now, I am ready to change job. The offer is good. The bad thing is
that they won't pay for my GC fee. I have to pay for the EAD renew etc.

Here is my question:

If I contiune use my current attorney, how much will he possible
charge after I-485 got approved?

I want to get an approximate number. So, I will be able to neogiate
with the lawyer.

Thank you in advance!

Hopefully, we all get GC soon!