These kinds of threads show up often..especially with regards to the W124s, which have now fully depreciated, yet require major refreshing of some sort which exceeds their value.

It's a good question, and if you ask my wife, she would say "upgrade". Personally, I was there a couple of years ago, facing a $2300 bill for a complete top-end overhaul (including head gasket). I still have to contend with replacing old suspension components and an ailing tranny, which will proabably top out at around $3000...but I still plan on keeping the car.

If the '01 was well maintained, it may be a better choice, despite having to carry a monthly car note...

__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car