Curious as to why you no longer use the Shopbot controller?
I sold just a 2013 PRS Alpha Shopbot controller, motors and associated wiring for $3k (Centroid upgrade), so you should be looking at $4k+ since you're including the spindle. Is the spindle VFD included too? What power rating is the spindle? What's the production year of the system?
Great package for someone who has a PRS standard with a router.
Good luck with the sale!
ShopBot Details:
2013 PRS 96x60x12 (Centroid upgrade)
4hp Spindle
12" indexer
Aspire
Rhino
Fusion 360
Ferrari 360
Prusa MK3S+