Take the Long View
That much replacement, when done, is like buying a new 250 wpc dual mono amp. That’s not a lot of money if you think of it that way.
You are paying for years of expertise, knowledge regarding parts selection, warranty ...
If you really liked it’s sound, consider how smart you are to have it fixed. What would you be depriving yourself of, for many years, because you thought he charged too much?
Only 30 minutes away? I would drive a few hours to see the shop, meet the people, save shipping cost and risk.
There is only 1 shop in the country recommended by McIntosh to work on my 1962 mx110z, it’s 5 hours away, you are quite lucky when you think that way.
If you asked them to give you a better price, you will never know if they then used lesser quality parts.
You would not be able to sell it in it’s current condition ....