The pump on my 240D went over 500,000 miles with zero attention. When it let go the bearing almost got in the engine.
I believe that if the mechanical portion including the bearing and arm are tight and smooth, a rebuild kit would be okay. But always keep in mind the possible consequences of a roller/arm failure. It could cost you an engine.
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in