The aftermarket TRW are crap just like Febi.At less than $130, it is almost guaranteed to be a Asian sourced part OR "Made in Unknown" like some Febi parts.
Ball joints are not a part to go bottom dollar on.
This is one case where OE Mercedes is the only way.
And they do last 20+ years, so I consider them a good buy.
Lionel has a good price on them.