There are none on ebay, and it won't find it as a completed search either. SG Megs as well if anyone can help.
Recent completed listings: Botcon 2008 Starscream | eBay and are you kidding me?: BOTCON LOT ARCEE STARSCREAM E HOBBY SCOURGE CLASSICS G1 RTS GENERATIONS | eBay
And from my own research in the past, I remember seeing him recently (past few months) in the $100-$125 range, loose and MISB. Megatron was around seems to have gone up to around $150 minimum over the last few months, but there have been so few available it's difficult to gauge.