Brake Booster Malfunction

I would just replace the master cylinder for $1300 or $1400 (you listed two different prices) and call it a day.

That installed price is decent assuming new parts; they may be getting a good Toyota discount on a pre-tariff part that could go away. Jump on it.

I don't understand why the pump costs $1800 installed, it is usually cheaper. Perhaps this part was hit with a tariff.

You could contact Toyota Corporate but it will be a waste of time on a 14 year old 190k car. Their 10 year 150k warranty on this system was already extended from the factory 3 year 36k mile warranty.

 

The main reason to replace both is because of cost. And it's very likely when one fails,
the other one is close behind.
There is a lot of work involved in removing each. So if you only replace one part, when the other
fails, you have to pay the labor, again. You may get lucky, and if you are willing to take that chance,
go for it.