I bought mine for $600 total. My dealer sold me a used module, display, and cables for $500. I bought the servo motor and cable directly from Perfect Pass for $100. My boat already had the paddle wheel standard, so I was set.
The deals are hard to find, but if you do enough calling around you can find one. A good tip.... when you call around to dealers looking for used components, speak with the service department first. They know what parts they have laying around and they can ask the sales manager/owner to give you a price.
The downside to buying used may be a lack of warranty, but Perfect Pass has such outstanding service that they will fix any defective components for you regardless of where you purchased them, as long as you pay to ship it back to them.