I own a Tron LE and never plan to sell it. So I don't care if the value goes up or down. That being said, previous reasons posted it's a $8500-$10K game based on limited quantity in US and time of year.
There's a lot of craziness on prices right now on pinside due to PPS and Stern rerunning titles. It's as if every title that was ever run "could" now be a remake or vault edition so everyone is throwing doubt on game values to drive prices down. If you want to wait 1, 2, 3 years to possibly be right on a remake no problem. If you want to play the game now, spend your money and enjoy the entertainment machine that it is.