2001/rx300

What is the best way to go.....re-man part or factory new? I know price is a big diff, but what about quality? I was told to look for orig used from salvage or bite the bullet and spend $$ for OEM. I don't know if it is true but was told non orig part does not have Platinum is why $$ is lower and the resistance will be diff and give the computer odd readings. Thanks for any input.