ORIGINAL: Broken Wings
The difference in price reflects the Solid Platinum coil used in a OS plug vs the Rhodium/Platinum Element. Solid Platinum coil is more expensive no matter who makes the glow plug...
Solid planinum is inferior to rhodium. And to my knowledge there are no longer any solid platinum plugs. Maybe a few racing plugs? OS doesn't make this claim. Cheap plug may have other metals other than platinum and rhodium, but solid platinum is not an advantage as they would be too soft. And wasn't it rhodium that improved heat at idle?
Presently platinum is about $1.720 per ounce and rhodium is $2,250 per ounce. So if OS is solid patinum instead of a platinum and rhodium, then it is the cheaper plug.