In MOST cases the difference between cheaper and more expensive product is not the substance itself (we are not talking about kitchen or basement “laboratories”) but oils used – big pharmaceutical giants certainly make it not painful, no irritation, etc. Sometimes (rarely) quality problems occur with top underground laboratories like with deceased British Dragon or even with small legal manufacturers like Balkan. This is not system, this is not often but such problems are unbelievable with Organon or Schering. So, double price normally means insurance against problems and convenience of usage, but not duplicate effect. And some UG labs are tempted to underdose the most expensive products, so reputation of particular laboratory should be studied before use, in the past we had some brands removed because of that.