It really is that simple. 

We are willing to provide additional documentation to support our request and discuss any potential steps to ensure a smooth and fair process for all parties involved.Thank you for your attention to this matter.

This is not specific tax advice.  

So essentially whom ever is paying them or they single out is the lender you get stuck with and it may not be the best one.

Is it desirable? 

Beyond that, real estate is largely local; in my market we are not seeing anywhere near those numbers.

So, they can markup what they paid out and keep the difference.Most PMC industry software has these two options built in.So, it's just a matter of understanding how your PMC is marking up maintenance and not expecting it to be for free.Regarding the specific charges you mentioned - there has to be some level of trust with your PMC. 

How limited is your knowledge base?

What David said is true. 

But nowadays pvc or pex is an easier fix.