Since I have a degree in Law, I can very well tell you that "yes", $2000 is an outrageous sum of money for a freaking "filing".
How much is he going to charge you later on, when he really starts to defend your case ? What will he defend exactly, because the case is already laid out. You applied 3 years ago, supplied every document IRCC requested and haven't got a decision yet. The Supreme Court I believe took out Covid as an excuse for IRCC to delay the application processing, so what is there left to argue ? Everything is already documented.
Law is pretty straight forward and categorized. A good memory, a law book and being able to communicate can take you far, especially for these simple cases.