the quality of drivetrain parts is paramount in my opinion. there is no reason whatsoever to save $5-$10 on cogs and lockrings. just buy the NJS stuff (not going on an NJS tyraid), it is'nt that expensive and you will know it is quality. the problem with the cheaper components is the metalurgy and machining. the shimano, EAI stuff that is stamped is going to last longer and be more reliable. the tolerances of production and quality metal alloys make a world of difference.