Honestly, Id have to ask this because the only real online reference check for this games going rate seems to be ebay, and I'd prefer to not just take someones word for it, is there any compiled list of legit completed transactions for this game from 2010 and 2011? And when I ask that I mean more then 2 or 3 just done on this forum? And I ask this because I know for a fact the last time I collected PCE stuff the game was going for $80 sumthin still (2007-2009). I know this because I had to research it and sell a copy for a friend a few years back.
And its unfortunate, but rare games do tend to simply go up in value as more people get into the hobby. Just like in any other market, a sudden influx of customers and not enough items to go around is going to drive up price of desired items. Its a part of supply and demand. Unless everyone agrees on a certain going price, AND is willing to partake in listing their own copies all at once in some meaningful number to set a new steady price trend, then there isn't much you can do but throw your hands up in the air and walk away if you don't like the current rates, ebay or otherwise. In other words its TOGTFO. The only other choice you have is to hold out and wait and maybe something will happen like what happened with Exile and Cosmic Fantasy 2, where a sudden influx of new sealed copies hit the market for cheap. While highly unlikely, it is possible.
Also, I think I have made my thoughts clear on this title before, but just for the sake of it I will repeat it here. Fun wise I don't view this game as worth getting for the $60-75 range unless you have 2 player ability and someone who would like to play this with you. As a single player game it is hard in spots and you may not feel the single player experience is worth the asking price. I definitely don't. Personally I don't even feel as a single player game you will get $50 bucks of fun out of it. This is one of those titles that to me you really need to load the rom up before buying and make sure you play it enough to decide how much its worth paying for, because its rarity dictates its value more then its fun/replay value. Then again, I feel the same way about Double Dragon 2 on Pce, and people pay stupid amounts for it all the time, way more then they spend on Shockman on average.