OPPO BDP-93 with Meridian Mod (4x spdif)

I am trying to sell my beloved OPPO BDP-93 with two modifications, 1) region free and more importantly 2) 4xspdif mod ($400 from JVB digital). I really don't know how to set my asking price for this specific unit. The $500 is nominal place holder, so please feel free to offer me with your price if you are interested in.
As you may know, 4x spdif mod is breaking 7.1 channel digital signal to 4 spdif digital outputs (see the pic for the ports). This format has benefit over conventional 2 ch toslink or coax because it can transfer all 7.1 channels with high resolution (24/96). 
I called it as "Merdian mod" in the title since the 7.1 channel is a perfect match with multi channel inputs of meridian processors. So this BDP 93 can be directly connected to meridian system without needing HDMI-multi channel digital converter such as HD621. That was the way I used this unit (for a few hundred hours total)
Functionally perfect condition. I saw one quarter inch long, very pale scratch on the top surface, but in general this unit is very good shape.
I am the original owner and have all original materials including remote, power cord, HDMI cable, wireless adapter, wireless adapter extension, box and package etc.
Please add 3% if you want to use paypal. Shipping to Conus will be on me at my asking price. Thanks.