WATER pump is out. Why do all of the auto repair folks charge $700-800 to repair it. I know that they have to replace the timing belt and maybe the tensioner and a few rollers,,but what the heck compared to a $400 bill in the past?

A requirement to fixing the vehicle includes, estimated costs of parts and technical installation fees. The extent to the damage requiring several parts that costs more would likely cost more in fees to install considering technicallity involved with vehicle.

The concern is about wanting to pay the same fee for the same defect on the same vehicle throughtout the vehicles duration. The technicallity of a vehicle get more complicated over duration of time.
1. The vehicle losses value through out the duration of existence. A requirement of wanting to keep it on the road only keeps requiring more resoures once the duration exeeds durability specification. A collaboration of yourself and technical expert could restore features whenver developements occur. However at a cost like mentioned. Your realisation of the issue has possible solutions.
2. Fixing the fault on one hand, or considering alternatives;
a. acquiring another vehicle e.g.

Its a big job. do not put it off. Replace th ebelt and tensioner, do not skimp, buy the best parts from the dealer. If that timing belt breaks, the valves will be bent, and it will never run again, unless you have $2000 to put into it. I'm not trying to scare you, just the facts.