Volvo Repair: 1993 940T how much do I spend on repairs?, bassis, heater core

Question
I have a 1993 940 turbo wagon with 135+ miles on it.  We are the 2nd owner and have had it for 20,000 miles. Today it needs a new heater core.  We have replaced the radiator within the past few months. (When we did that we thought that would fix the problem, hoping it wasn't the heater core.)  

Oh well, here we are today.  For the time the heater core is bipaseed.  For now it is okay considereing the temperature is ranging from  the 80s to over 100.  Come the fall I will need heat again.

This is the family car and we have 2 children under the age of 4.  Is it time to think about trading this car in or do we face this reapir? What is the track record on the 940 turbos?  We have done some electrical switch replacement and need to do the drivers side window switch, which means the whole unit. The interior is showing ware too.

Faithful volvo driver. This is our 4th volvo.

Thank you!!!

Answer
they are a very reliable car.I always feel trading a car has many questions you must consider.do I want a new car or do I really like this one?how bad of shape is the car in?(interior or paint wise)can I afford  car payments or do I want a car payment?with high miles anything can go wrong.most to worry about would be the transmission or turbo going bad.which at this mileage is possible but does not happen on a regular bassis on these espedcially if it was maintained well.