Shawn - That test track is scary! Glad you didn’t run it off the end 
Shawn,
I think you are in the ballpark. The Phoenix sound is a little dated but is still useful. I got a 2 truck shay with Bigsound 97 and was able to adapt it to batt and Airwire. I paid $200 for it. You system is a little more updated so it could be a little higher price.
One thing that I did get nailed on is my loco was baught from a widow and the engine hadnt been ran in a while. The gears were split on it. I bought the NWSL replacement ones and it was a quick fix. The gears were around $12 a piece and you need 4 of them. You could sweeten the pot and include the gears and that might make your auction more valuable.
Or just trade with Jon, it would seem better to trade with a LSC member than let it go to an ebayer.