Knowing how meticulous you are with your toys coupled with how hot the used market is right now, you will likely get a good price for it. While not for everybody, the open back set up is a rare find and will be a big plus for the right buyer.
I have always bought mine "right". If cared for, Parkers seem to appreciate at a fairly steady rate. After 5 years of ownership I managed to sell near what I paid. My gut tells me $135k would be a good place to start and would attract serious buyers.
Like johnkn said, if you can find some past sales info that will give you a feel of the market pricing. I would look up the blue book value to use as a guide but in the end it depends on how bad someone wants it and what they are willing to pay. Last resort would be to let a dealer sell it. When I sold my boat the dealer suggested they list it for $7,000 less than the price I sold it for myself and they would take a commission out of the sale.