As a 100% modifying idiot I can only advise you to modify a car that you want to keep for a longer time. If you want to sell the car, it is a waste of money...
You say you can buy parts from an used car...If you can get the door and fender panels incl. the lower body moldings (I presume that these are the skirts over the thresholds?) for a reasonable price and you think you should modify your car anyways; it is a very easy job.
In the Netherlands I would have to pay approx. $450,- for a used set of panels and skirts. The front and rear bumpers are the same as on the 1989-1993 W124's. The chrome trims on the front and rear bumper can be drilled onto your own bumpers) you only need to repaint them).
Fender trims can be pulled of; they are clicked on. Start at the wheel bottom side of the front fender panels and at the door top site of the rear fender panels.
The door panels are fixed with two screws each (to be removed from the inside of the doors). The bottom of the panels can be pulled loose (simple clamps) and the top of the door panels has to be shoved to the back.
The lower body moldings have a rubber trim in it. Remove this rubber trim and unscrew the screws you get to see. At the underside of the moldings is another set of screws to be untightened. After these screws, the front and rear fender panels and the door panels are removed the molding can be taken off.
If you want to mount this molding to your own car, you have to file the currently round upper holes square and you have to drill in the bottom fixings (and file them square as well).
I only modify a car when I want to keep it for a longer period; you will never get the extra financial input back when you sell it.
with a minor 600+k