Uber expensive repair at United Radio

Mmmm, did that include the price of the chipsets?  You paid full boat + mark-up....

Proper dis- & re-assembly, testing before & after, time spent discerning and ordering the proper replacements, blah blah....

Still seems a bit much, but...it's not my business to fix your bits.
Nice bits, bills the fits.

Skill & experience counts....your $, as it changes hands. ;)

I’m not in the US, but I have never found that good audio repair has to be expensive. It is amazing the services you can turn up with a little ’outside the box’ research.
I found a guy less than 10 miles from me who has thousands of hours experience, and works out of a workshop in his back garden. I have taken equipment of all sorts both valve and SS to him for repair, and have never been disappointed at the results or the price. So the right service at the right price is probably available somewhere near you, it’s probably just not well advertised so you haven’t found it. https://www.facebook.com/RussAudio-258730347512577
This is a job I had done recently at around £350 https://www.facebook.com/permalink.php?story_fbid=4158294247556148&id=258730347512577
There is a modification that he did FOC that isn’t mentioned there, he also added a few components to elevate the heaters by 50 Volts.
This is another job I had done at around £450 https://www.facebook.com/permalink.php?story_fbid=4009448215774086&id=258730347512577

imho, it’s poor form to play Monday morning quarterback when you failed to perform the necessary due diligence of getting a second opinion when you had doubts about the original estimated cost of repair.  

I know first hand that quality audio equipment repair doesn’t come cheaply, but the price the OP got charged seems exorbitant.  

It is often the case that repair places will charge a fixed rate for the diagnosis, such as the one hour time, even though it might take much longer.  The fixed rate protects the customer; the customer is not charged for several hours only to find out the item is unrepairable.  That $140 does not cover the expense and time involved in unboxing, potentially boxing up and shipping the item if a repair is not attempted, so there is some incentive for the shop to investigate even this exceeds that one hour diagnostic time, with the hope of recouping the extra cost via the repair job.  If the repair is approved, I would expect that extra time diagnosing to be added to the total repair time.

As to the total of 14 hours, this does seem to be a lot of time, but, you seem to have the experience to have made an assessment at the time an estimate was provided.  If you had told them this was too much and you would just pay for the assessment and you want the amps back, they might have found a way to lower the price.  The $140 to check out your amp and do nothing else would clearly be a loss to the shop.  I don't like to haggle, so I would have probably just accepted the estimate, but, this is clearly an issue with you; the problem is that you should have acted before, not after, the repair.