Ive been a mechanic for close to 30 yrs now,and the only thing Ill add is that when you buy a cheap beater car,you have to be able to do some of the repairs yourself...if not,it will nickel and dime you as much as a car payment.I run old vehicles,by choice.I have an 11 and 12 yr old truck and an 8 yr old car,I just gave my daughter my 15 yr old car...So im always working on something it seems...but this is the price we pay for not having a car payment,cheap insurance and a large investment...so when something is amiss,roll up your sleeves,and get down on the ground and find out whats going on..grab a flashlight and learn...If your not sure of something,ask here or a friend,dont get in over your head,but you have to start somewhere.
A good place would be your leaky cooler line,if its dripping,it needs to be replaced,and when it fails(and it will),you will likely run the trans out of fluid before you realize it happened,burning it up if your lucky,possibly catching the car on fire,worst case..most cooler lines are under pressure when the torque convertor is locked! My truck runs 175psi in the cooler line at times! I verified this with a pressure guage.This is no place for leaks of any kind...
My advice it try another mechainc if you cant do this yourself...800 seems like a lot for trans cooler lines on a fwd car,they are little short lines,they usually rust out or leak at the preform rubber/steel unions...you can buy the new line from chrysler,and probably do this yourself for under 200 if you wanted,heck the lines probably under 100.00.
One last thing,stay on top of the oil on that 2.7 Chrysler..its not a good engine,as you know..but ive seen some run forever,and many fail under 60K miles...so you seem to have a good one.