Perhaps the aftermarket price of Omega Supreme has been depreciated by the reissue, which was a big shelf-warmer (and thus readily available for some time). I personally still saw Encore Omega Supreme shelf warming as late as 2012 (some four years after its release; that's Combiner Class Devastator level of shelfwarmage!)
<shrugs>
P.S.: Should this thread be merged with the Price Check/What's It Worth? thread?