If you have been looking at W124s a while, you probably already know that they are absent of any woodgrain appointments. That came around '93 (I think). But you also don't have to deal with cracks in the veneer (primarily on the console).
The evaporator is buried deep in the recesses of the cockpit, so replacement calls for stripping the dashboard completely out of the car. With today's labor rates, that's $1500+ just for that.
Fortunately, mine went dead during the extended warranty period, so I was just out the $250 deductible.
The great thing about these cars is ease of maintenance. Parts are relatively inexpensive, and you only need a few specialized tools to get really dangerous. Invest in a metric allen socket set for starters...
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car