I recommend you buy them from digikey or mouser or try to find deals on well known manufacturers or lots.
the only half decent chinese brand I found was Uni-T. They are kinda decent, but you need to make sure you are not getting the super stiff PVC ones (but at least they did not skimp on conductors for me).
I think my uni-t banana to banana were uni-t brand all silicone, but I on another continent right now from my lab.
Anything else you are liable to get literarly magnetic wire thats like a 1 ohm per meter or more,