Changed the front ball joint arm yesterday with the part sourced from a local motor factor at approx £90 inc vat. Looking at fleabay before and saw I could have bought same part for as little as £36 plus £5 p+p.
Is there really that much difference in pattern parts quality that you would shun away from the second part in favour of the first ?

don't know about RR parts, but in the aircooled Porsche world the genuine items can be noticablly better quality ---- last example of this was the special tapered pin/bolt that locates lower ball joint to the main strut , OEM part didn't fit well at all, bought a genuine one & it was perfect fit

Of course, the same is also tru that some aftermarket parts are better quality the genine stuff