For the 3rd party Genesis, also remember that's $300 in US Dollars, not Australian, and also doesn't include shipping

So it will be at least $400 probably more!
Platinum edition on the other hand is a quarter of that price. Its a large figure, and is a good display piece as a classics Omega. It looks good with generations figures, towering over even voyager figures. It may be a overly simple transformer, so its lacking. For this reason its understandable that people who already own the Energon version in the past want to avoid it.
Looking forward to when Hasbro finally gets to doing a proper Omega Supreme with a brand new mold.