Dealing with being overcharged by lawyers

What is your CTFAR advice about handling conflict with a lawyers bill. I signed an engagement letter with a lawyer. He said he charges 675/hr to consult for me about a tax situation. He was the (only) senior partner (his firm). At the time I thought he’d help me deal with paperwork, too, but it turns out it was just for a memo. I did try to get as clear as possible, up front, what the work would entail and that any hours above a predetermined amount would be discussed before charged. I also asked if a Jr person could do some of the work at a lower cost and I was told, no, no Jr person could do this work. We agreed on 8-10 hrs at the rate above.

It became apparent that this lawyer did not do the work-his senior tax manager did the work, who has a BA in accounting, no degree in law, and I believe would not normally get $675/hr. The best lawyers in my town get $600-$800/hr. I would consider the sr tax manager a Jr person working under him.
I received the bill for just under the estimate of 8-10 hrs (9.2 hrs) at the full fee 675/hr. It also turns out that their response was pretty cookie cutter – they probably knew in 1 hr what to do and then about 3 hrs to number crunch and send me a memo.

I also had to follow up about 4 times with them.

I did learn a lot from conversations with the Sr Tax manager- all told about an hour- and another 30 minutes with her and the lawyer yesterday

I want to negotiate this down to something I think is fairer, maybe $400/hr for the time.

When I think of this right now, I get dread.

Can you help me with CTFAR?

C-Lawyer bill
T- He is screwing me, and I am powerless over this, I cant help myself
F-dread, powerlessness, panic, dizzy
R- eventually paying too much, feeling walked over, feeling exploited

C-Lawyer bill
T-This bill is too high for a junior person to do the work-I also believe the job was cookie cutter and not original-I believe the rate is too high-and I believe the lawyer is exploiting the situation by not being up front with the invoice that a Jr person worked on it for a lower fee-I am saddened that it is not fairer than this, I don’t know why he would have been this way, and I want to dispute the bill
F-uncomfortable but not stepped on and squashed
A-I will get input from a number of people and write him an email with a negotiated price
R-I will feel like I am dealing with the situation fairly to myself