You either didn't do enough research or don't believe what you read if you think the AC evaporator is the only major item to be concerned with in a W140

Timing chains in the M119 are a little more robust than in the M116/7. General thought is to plan replacement between 150 and 200K. It's a much more involved job because of the DOHC arrangement but with the right tools it shouldn't take much longer.

Get a PPI because there's more that can go wrong than just the evaporator.

If the cam oiling tubes break you'll wear the cam and/or lifters quickly. A ticking noise caught early can save an expensive repair.

Donnie says to walk away from any M119 with sludge under the valve covers. I forget why.

Caps, rotors and plug wires are over $500 a set and tend to not last long enough. SteveB says they can look terrible and work properly but many shops see the telltales of arcing and general wear and replace parts. I generally know my way around engines and it took me over 4 hours to replace these parts in my 95 S420. Not sure what book time is but I expect it's not a $49.95 deal at a tune-n-lube place.

Closing assist pump failure is annoying but closing the doors and trunk harder gets around it. Usually you can adjust the max pressure sensitivity of the pump so you don't hit the cycle time limit that shuts down the pump.

PSE pump failure is worse because you lose central locking and other features.

The stereo sounds great when it works but if it has pops or missing channels it's costly to have the amplifier repaired. The amp and speakers are a matched set so an aftermarket amp pretty much means aftermarket speakers all around.

94 was a bad year for engine bay wiring harness insulation. It's too common for cars of this vintage to have the check engine light to report random failures as a result. A replacement harness is not that expensive but figuring out that's what you need can be time consuming.

$5000 is a great price for a W140 but it could be that the owner is tired of throwing $2000 repairs at it every few weeks.

Sixto
93 300SD