I use to work for the company that rebuilds auto zones parts and your right.They do use the cheaper version of brushes diodes voltage regulators in almost all there reman parts.The odd thing is nappa car quest orileys pep boys advance were our customers.Each parts company has certain requirements for there parts .I guess it is your choice buy cheap get cheap .I like to have my parts rebuilt locally if it electrical.Now I rebuild my own steering gear boxes window lifts wiper motors and drive shafts.