It may always pay to at least price the oem parts before buying aftermarket. They in general lasted very well on 123s etc.
Some german aftermarket front end parts for volkswagon diesels we thought were good for only about a year or so. Aftermarket parts can be false value if you intending to keep your car long term sometimes. On the otherhand if the archives identify really good aftermarket brands for our cars. Why not use them if money is saved.