103,000 03 ML350 DUMP IT OR KEEP IT?

[lincolnmatthews]

Would like some opinions? Wife's been driving this for over 5 yrs, mostly short trips. At 100,000 the water pump & alt. went out had that replaced. We have a loud lifter when cold, (trying to keep oil changed at 7500 miles). Its had proper maintenance, cooling system, brakes, tranny all serviced (fluids changed) at about 60,000.
But we couldn't get the fuel filter changed, we took it in twice to the dealer & they were unable to "release" the tubing from the filter! They said the factory installed it wrong so they will probably ruin the lines. They would have to be replaced for a cost of around $1500. WTH's up with this?
Also it apparently needs ball joints already & all vacuum lines replaced, tires & brakes.
After reading here about the 3.5 counterbalance shaft & gear issues (which I guess doesn't affect our 2003, right?) Who knows with MB anymore.
We don't know whether to keep it for another 50,000 or trade it on something, not another MB for sure!
This isn't our 1st MB I had a 300CE for along time, other than head gaskets it was a great car. I currently have a 83 300CD I've owned for years, we all know there reputations.
Just unsure about these ML's thanks for your help!